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Kong J, Wang J, Han Q, Li G, Peng GD. Effects of a UV absorber in silica-loaded resin on DLP silica fiber preform fabrication. APPLIED OPTICS 2024; 63:D7-D13. [PMID: 38856327 DOI: 10.1364/ao.516246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/02/2024] [Indexed: 06/11/2024]
Abstract
3D printing technologies have distinguished advantages in manufacturing arbitrary shapes and complex structures that have attracted us to use digital light processing (DLP) technology for specialty silica optical fiber preforms. One of the main tasks is to develop an appropriate recipe for DLP resin that is UV sensitive and loaded with silica nanoparticles. In this work, the effects of a UV absorber in highly silica-loaded resin on DLP printing are experimentally investigated. Spot tests and DLP printing are carried out on resins with varying dosages of a typical UV absorber, Sudan Orange G. Based on the experimental results, the UV absorber can significantly improve the resolution of DLP printed green bodies while requiring a larger exposure dose.
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2
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Struk-Sokołowska J, Faszczewska A, Kotowska U, Mielcarek A. Comparison of benzotriazole ultraviolet stabilizers (BUVs) removal from wastewater after subsequent stages of sequencing batch reactor (SBR) treatment process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169813. [PMID: 38184258 DOI: 10.1016/j.scitotenv.2023.169813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/02/2023] [Accepted: 12/29/2023] [Indexed: 01/08/2024]
Abstract
The research focused on benzotriazole ultraviolet stabilizers (BUVs) which are commonly used compounds despite being found dangerous, e.g. promoting breast cancer cell proliferation, damaging vital organs such as hearts, brains livers and kidneys. The aim of the study was to analyse the efficiency and removal rate of BUVs from wastewater depending on the quantity of tested compounds and SBR anaerobic-aerobic conditions. The study was conducted in sequencing batch reactors (SBRs - 17 L) with real flocculent activated sludge (8 L) and model wastewater (5 L) containing UV-326, UV-327, UV-328, UV-329 and UV-P from 50 to 600 μg∙L-1. The SBR were operated in 390 cycles of 7 h and 10 min over 130 days. The similarity of the technological parameters of the treatment process to those used in a real wastewater treatment plant was maintained. Efficiency removal of individual BUVs was strictly dependent on the dose of compounds introduced into wastewater and ranged from 68.2 to 97 %. Removal of UV-329 occurred with lowest efficiency (from 68.2 to 85.2 %) while UV-326 was most efficiently removed from the wastewater (from 94.1 to 97 %). UV-329 was removed from wastewater with the lowest (0.0968-0.9524 μg∙L-1∙min-1) average removal rate while UV-327 with the highest (0.16-1.3357 μg∙L-1∙min-1), irrespective of BUVs dose in the influent. Secondary release of BUVs into the wastewater occurred in SBR during the settling phase and was dependent on the type and concentration of the BUVs in the raw wastewater. This occurrence was noted for UV-326 ≥ 100; UV-327 = 600; UV-328 ≥ 200; UV-329 ≥ 50 and UV-P ≥ 100 μg∙L-1. The settling phase needs to be shortened to the required minimum. This is an important conclusion for WWTPs in regards to SBR cycle duration and technological parameters of the treatment process.
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Affiliation(s)
- Joanna Struk-Sokołowska
- Białystok University of Technology, Faculty of Civil Engineering and Environmental Sciences, Wiejska 45A, 15-351 Białystok, Poland.
| | - Alicja Faszczewska
- Białystok University of Technology, Faculty of Civil Engineering and Environmental Sciences, Wiejska 45A, 15-351 Białystok, Poland
| | - Urszula Kotowska
- University of Bialystok, Faculty of Chemistry, Ciołkowskiego 1K, 15-245 Białystok, Poland.
| | - Artur Mielcarek
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Warszawska 117a, 10-719 Olsztyn, Poland.
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3
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Li X, Liu Y, Luo B, Xiang W, Chen Z. Effect of apple polyphenols on physicochemical properties of pea starch/pulp cellulose nanofiber composite biodegradable films. Int J Biol Macromol 2024; 257:128480. [PMID: 38052284 DOI: 10.1016/j.ijbiomac.2023.128480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/23/2023] [Accepted: 11/26/2023] [Indexed: 12/07/2023]
Abstract
A pea starch (PS) and pulp cellulose nanofibers (CNF-P) hybrid matrix biodegradable film was prepared using apple polyphenol (AP) as the active substance. SEM and thermogravimetric analyses showed that apple polyphenols could be uniformly distributed and form hydrogen bonds with the matrix, and the increase in crystallinity improved the thermal stability of the films (the final residue of the films increased from 22.66 % to 31.82 %). The TS and EAB of the films reached their maximum values of 11.14 ± 1.73 MPa and 71.55 ± 8.8 %, respectively, at an AP content of 1.5 %. It should be noted that the antioxidant properties of the films were significantly positively correlated with the AP content, and the DPPH radical scavenging rate of the films reached 73.77 % at an AP content of 4.5 %, which was about 49 times higher than that of the control film. The same trend was observed in the UV-vis spectra. In addition, the total color difference and water solubility of the membranes increased from 4.29 ± 0.29 to 31.86 ± 1.90 and from 20.01 ± 0.97 % to 21.70 ± 1.99 %, respectively, and the biodegradability also showed an upward trend. These findings provide a theoretical basis and data support for the development of multifunctional biodegradable food packaging materials.
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Affiliation(s)
- Xu Li
- School of Food and Bioengineering, Xihua University, Chengdu 610039, China; Chongqing Key Laboratory of Speciality Food Co-Built By Sichuan and Chongqing, Chengdu 610039, China; Key Laboratory of Food Microbiology of Sichuan, Xihua University, Chengdu 610039, Sichuan, China.
| | - Yao Liu
- School of Food and Bioengineering, Xihua University, Chengdu 610039, China
| | - Bangping Luo
- School of Food and Bioengineering, Xihua University, Chengdu 610039, China
| | - Wenliang Xiang
- School of Food and Bioengineering, Xihua University, Chengdu 610039, China; Chongqing Key Laboratory of Speciality Food Co-Built By Sichuan and Chongqing, Chengdu 610039, China; Key Laboratory of Food Microbiology of Sichuan, Xihua University, Chengdu 610039, Sichuan, China
| | - Zhiwei Chen
- School of Food and Bioengineering, Xihua University, Chengdu 610039, China; Chongqing Key Laboratory of Speciality Food Co-Built By Sichuan and Chongqing, Chengdu 610039, China; Key Laboratory of Food Microbiology of Sichuan, Xihua University, Chengdu 610039, Sichuan, China
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4
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Devitt G, Johnson PB, Hanrahan N, Lane SIR, Vidale MC, Sheth B, Allen JD, Humbert MV, Spalluto CM, Hervé RC, Staples K, West JJ, Forster R, Divecha N, McCormick CJ, Crispin M, Hempler N, Malcolm GPA, Mahajan S. Mechanisms of SARS-CoV-2 Inactivation Using UVC Laser Radiation. ACS PHOTONICS 2024; 11:42-52. [PMID: 38249683 PMCID: PMC10797618 DOI: 10.1021/acsphotonics.3c00828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/03/2023] [Accepted: 11/03/2023] [Indexed: 01/23/2024]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) has had a tremendous impact on humanity. Prevention of transmission by disinfection of surfaces and aerosols through a chemical-free method is highly desirable. Ultraviolet C (UVC) light is uniquely positioned to achieve inactivation of pathogens. We report the inactivation of SARS-CoV-2 virus by UVC radiation and explore its mechanisms. A dose of 50 mJ/cm2 using a UVC laser at 266 nm achieved an inactivation efficiency of 99.89%, while infectious virions were undetectable at 75 mJ/cm2 indicating >99.99% inactivation. Infection by SARS-CoV-2 involves viral entry mediated by the spike glycoprotein (S), and viral reproduction, reliant on translation of its genome. We demonstrate that UVC radiation damages ribonucleic acid (RNA) and provide in-depth characterization of UVC-induced damage of the S protein. We find that UVC severely impacts SARS-CoV- 2 spike protein's ability to bind human angiotensin-converting enzyme 2 (hACE2) and this correlates with loss of native protein conformation and aromatic amino acid integrity. This report has important implications for the design and development of rapid and effective disinfection systems against the SARS-CoV-2 virus and other pathogens.
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Affiliation(s)
- George Devitt
- School
of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Institute
for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Peter B. Johnson
- School
of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Institute
for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Niall Hanrahan
- School
of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Institute
for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Simon I. R. Lane
- School
of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Institute
for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Magdalena C. Vidale
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Bhavwanti Sheth
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Joel D. Allen
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Maria V. Humbert
- Clinical
and Experimental Sciences, Faculty of Medicine, University of Southampton,
Sir Henry Wellcome Laboratories, University
Hospital Southampton, Southampton SO16 6YD, United
Kingdom
- University
of Cambridge, MRC Toxicology Unit, Cambridge, CB2 1QR, United Kingdom
| | - Cosma M. Spalluto
- Clinical
and Experimental Sciences, Faculty of Medicine, University of Southampton,
Sir Henry Wellcome Laboratories, University
Hospital Southampton, Southampton SO16 6YD, United
Kingdom
- Southampton
NIHR Biomedical Research Centre, Southampton
General Hospital, Southampton SO16 6YD, United
Kingdom
| | - Rodolphe C. Hervé
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Karl Staples
- Clinical
and Experimental Sciences, Faculty of Medicine, University of Southampton,
Sir Henry Wellcome Laboratories, University
Hospital Southampton, Southampton SO16 6YD, United
Kingdom
- Wessex Investigational
Sciences Hub, University of Southampton Faculty of Medicine, Southampton General Hospital, Southampton SO16 6YD, United Kingdom
- Southampton
NIHR Biomedical Research Centre, Southampton
General Hospital, Southampton SO16 6YD, United
Kingdom
| | - Jonathan J. West
- Institute
for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Cancer
Sciences, Faculty of Medicine, University
of Southampton, Southampton SO16 6YD, United
Kingdom
| | - Robert Forster
- M Squared
Lasers, Limited, 1 K
Campus, West of Scotland Science Park, Glasgow, G20 0SP, United
Kingdom
| | - Nullin Divecha
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Christopher J. McCormick
- Clinical
and Experimental Sciences, Faculty of Medicine, University of Southampton,
Sir Henry Wellcome Laboratories, University
Hospital Southampton, Southampton SO16 6YD, United
Kingdom
| | - Max Crispin
- School
of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Nils Hempler
- M Squared
Lasers, Limited, 1 K
Campus, West of Scotland Science Park, Glasgow, G20 0SP, United
Kingdom
| | - Graeme P. A. Malcolm
- M Squared
Lasers, Limited, 1 K
Campus, West of Scotland Science Park, Glasgow, G20 0SP, United
Kingdom
| | - Sumeet Mahajan
- School
of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Institute
for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
- Department
of Biotechnology, Inland Norway University
of Applied Sciences, Holsetgata 22, N-2317 Hamar, Norway
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Malik Z, Parveen R, Zahiruddin S, Gautam G, Husain SA, Ahmad S. HPTLC Stability Indicating Analytical Method of Andrographolide and 5-fluorouracil with Network Pharmacology Analysis against Cancer. Comb Chem High Throughput Screen 2024; 27:894-909. [PMID: 37303181 DOI: 10.2174/1386207326666230609104038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 05/01/2023] [Accepted: 05/11/2023] [Indexed: 06/13/2023]
Abstract
BACKGROUND Herbal drugs when used in combination with chemotherapeutic drugs can reduce the side effects and increase the efficacy by acting on multiple targets. Andrographolide (AG), a diterpene lactone isolated from Andrographis paniculata Nees, is a bioactive compound with anticancer potential, and 5-fluorouracil (FU), a pyrimidine analogue, is used in the treatment of cancer. Both drugs are used to formulate combination nanoformulation to increase absorption, thereby increasing their oral bioavailability. OBJECTIVE The study aimed to develop and validate stability indicating simultaneous HPTLC method for quantification of FU and AG in combination nanoformulation along with in silico docking and network pharmacology analysis to understand the interaction between the drugs and cancer targets. METHODS Chromatographic separation was performed using mobile phase chloroform: methanol: formic acid (9: 0.5: 0.5, v/v/v) on HPTLC silica plates 60 F254 as a stationary phase using UV-Vis detector and HPTLC scanner at 254 nm. Further, in silico docking analysis was performed to predict the binding affinity of AG and FU with different proteins and network pharmacology to find out the exact biomolecular relationship of AG and FU in alleviating cancer. RESULTS The data from the calibration curve showed a good linear regression relationship with r² = 0.9981 (FU) and r² = 0.9977 (AG) in the concentration range of 0.1-2.0 μg/mL. The developed method was validated according to the ICH guidelines. Stability studies showed changes in peak patterns and areas. Bioinformatic and network pharmacology analyses of AG and FU with target proteins and genes associated with cancer play a multimechanistic role in alleviating cancer. CONCLUSION The developed method has been concluded to be robust, simple, precise, reproducible, accurate, and stability indicating for simultaneous quantification of AG and FU, and the molecular interaction studies have further indicated that the combination nanoformulation of AG and FU could be effective against cancer.
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Affiliation(s)
- Zoya Malik
- Human Genetics Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi-110025, India
- Centre of Excellence in Unani Medicine (Pharmacognosy and Pharmacology), Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India-110062
| | - Rabea Parveen
- Centre of Excellence in Unani Medicine (Pharmacognosy and Pharmacology), Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India-110062
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi-110062, India
| | - Sultan Zahiruddin
- Centre of Excellence in Unani Medicine (Pharmacognosy and Pharmacology), Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India-110062
| | - Gaurav Gautam
- Centre of Excellence in Unani Medicine (Pharmacognosy and Pharmacology), Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India-110062
| | - Syed Akhtar Husain
- Human Genetics Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi-110025, India
| | - Sayeed Ahmad
- Centre of Excellence in Unani Medicine (Pharmacognosy and Pharmacology), Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India-110062
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6
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Sansul S, Yousif E, Ahmed DS, El-Hiti GA, Kariuki BM, Hashim H, Ahmed A. Pendant Modification of Poly(methyl methacrylate) to Enhance Its Stability against Photoirradiation. Polymers (Basel) 2023; 15:2989. [PMID: 37514379 PMCID: PMC10386564 DOI: 10.3390/polym15142989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/06/2023] [Accepted: 07/08/2023] [Indexed: 07/30/2023] Open
Abstract
Photostabilization of functional polymeric materials is important for protection against aging and ultraviolet (UV) irradiation. There is, therefore, the impetus to modify polymers to increase their resistance to photodegradation and photooxidation on extended exposure to UV light in harsh conditions. Various polymeric additives have been designed and synthesized in recent years, and their potential as photostabilizers has been explored. Reported here is the effect of pendant functionalization of poly(methyl methacrylate) (PMMA) through organometallic moiety incorporation into the polymer's backbone. The reaction of PMMA with ethylenediamine leads to the formation of an amino residue that can react with salicylaldehyde to produce the corresponding Schiff base. Adding metal chlorides (zinc, copper, nickel, and cobalt) led to the formation of organometallic residues on the polymeric chains. Thin films of modified and unmodified PMMA were produced and irradiated with UV light to determine the effect of pendant modification on photostability. The photostabilization of PMMA was assessed using a range of methods, including infrared spectroscopy, weight loss, decomposition rate constant, and surface morphology. The modified PMMA incorporating organic Schiff base metal complexes showed less photodecomposition than the unmodified polymer or one containing the Schiff base only. Thus, the metals significantly reduced the photodegradation of polymeric materials. The polymer containing the Schiff base-cobalt unit showed the least damage in the PMMA surface due to photoirradiation, followed by those containing nickel, zinc, and copper, in that order.
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Affiliation(s)
- Shaymaa Sansul
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Dina S Ahmed
- Department of Chemical Industries, Institute of Technology-Baghdad, Middle Technical University, Baghdad 10074, Iraq
| | - Gamal A El-Hiti
- Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia
| | - Benson M Kariuki
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Hassan Hashim
- Department of Physics, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Ahmed Ahmed
- Polymer Research Unit, College of Science, Al-Mustansiriyah University, Baghdad 10052, Iraq
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7
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Emad N, El-Hiti GA, Yousif E, Kariuki BM. Metal Oxide Nanoparticles Containing Clotrimazole to Suppress Photodegradation of Poly(Vinyl Chloride) Thin Films. Polymers (Basel) 2023; 15:polym15071632. [PMID: 37050246 PMCID: PMC10096931 DOI: 10.3390/polym15071632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Pol(vinyl chloride) or PVC has functional properties that enable its use in many industrial applications. It suffers from aging, however, in harsh conditions (e.g., elevated temperature or high humidity levels) if oxygen is present. One way to enhance the photostability of PVC is to blend it with additives. Thus, thin films were made by mixing PVC with clotrimazole, and five metal oxide (titanium, copper, cobalt, chromium, and nickel oxides) additives. The metal oxides and clotrimazole were added at concentrations of 0.1 and 0.5% by weight, respectively. The effect of the metal oxide nanoparticles accompanied by clotrimazole on the photodegradation of PVC was then assessed. The results indicated that the additives have a stabilizing effect and protect PVC against photodegradation significantly. The formation of polymeric fragments of small molecular weight containing carbon-carbon double bonds and carbonyl groups was lower in the blends containing metal oxide nanoparticles and clotrimazole than in unblended PVC. Similarly, the decrease in weight was much less for the films blended with additives. Additionally, surface analysis of the irradiated polymeric films showed significantly lower damage in the materials containing additives. The most effective additive in the stabilization of PVC was nickel oxide nanoparticles. The metal oxides are highly alkaline and act as scavengers for the hydrogen chloride produced during the photodegradation of PVC. They additionally act as peroxide decomposers. In contrast, clotrimazole can absorb harmful radiation and act as an ultraviolet absorber due to its heteroatom and aromatic content. Thus, the use of a combination of metal oxide nanoparticles and clotrimazole led to significant improvement in the resistance of PVC toward photodegradation.
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8
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Kim HS, Lee KY, Jung JS, Sin HS, Lee HG, Jang DY, Lee SH, Lim KM, Choi D. Comparison of migration and cumulative risk assessment of antioxidants, antioxidant degradation products, and other non-intentionally added substances from plastic food contact materials. Food Packag Shelf Life 2023. [DOI: 10.1016/j.fpsl.2023.101037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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9
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Dehnou KH, Norouzi GS, Majidipour M. A review: studying the effect of graphene nanoparticles on mechanical, physical and thermal properties of polylactic acid polymer. RSC Adv 2023; 13:3976-4006. [PMID: 36756574 PMCID: PMC9891084 DOI: 10.1039/d2ra07011a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/11/2023] [Indexed: 01/28/2023] Open
Abstract
Polylactic acid (PLA) is a linear aliphatic polyester thermoplastic made from renewable sources such as sugar beet and cornstarch. Methods of preparation of polylactic acid are biological and chemical. The advantages of polylactic acid are biocompatibility, easily processing, low energy loss, transparency, high strength, resistance to water and fat penetration and low consumption of carbon dioxide during production. However, polylactic acid has disadvantages such as hydrophobicity, fragility at room temperature, low thermal resistance, slow degradation rate, permeability to gases, lack of active groups and chemical neutrality. To overcome the limitations of PLA, such as low thermal stability and inability to absorb gases, nanoparticles such as graphene are added to improve its properties. Extensive research has been done on the introduction of graphene nanoparticles in PLA, and all of these studies have been studied. In this study, we intend to study a comprehensive study of the effect of graphene nanoparticles on the mechanical, thermal, structural and rheological properties of PLA/Gr nanocomposites and also the effect of UV rays on the mechanical properties of PLA/Gr nanocomposites.
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Affiliation(s)
- Kianoush Hatami Dehnou
- Department of Materials Science and Engineering, School of Engineering, Shiraz University Shiraz Iran
| | - Ghazal Saki Norouzi
- Chemical Engineering Department, Faculty of Engineering, Razi University Iran
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10
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Enhancement of Photostabilization of Poly(Vinyl Chloride) in the Presence of Tin-Cephalexin Complexes. Polymers (Basel) 2023; 15:polym15030550. [PMID: 36771851 PMCID: PMC9918989 DOI: 10.3390/polym15030550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Poly(vinyl chloride), PVC, has many attractive properties, including low cost of manufacture, resistance to acid and alkali corrosion, and ease of molding. However, PVC suffers from aging in harsh conditions, leading to the shortening of its useful life. Stability to irradiation, for example, can be improved through the incorporation of additives to PVC. The design, synthesis, and application of new stabilizers continue to attract attention. The current work investigates the effect of three tin-cephalexin complexes on the stability of PVC on irradiation with ultraviolet (UV) light (λ = 313 nm) at 25 °C for a long duration. The PVC was blended with tin-cephalexin complexes at low concentrations (0.5% by weight), and thin films (around 40 µm) were made from the mixed materials. Various methods, including weight loss, infrared spectroscopy, and surface inspection of irradiated films were used to investigate the role played by these additives in the inhibition of PVC photodecomposition. The results confirmed that the additives led to a significant reduction in the rate of photodecomposition of the PVC blends. Tin-cephalexin complexes can absorb harmful radiation, deactivate hydrogen chloride, and scavenge high-energy species such as peroxides, therefore acting as stabilizers for PVC.
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11
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Construction of a Chitosan/ZnO-Based Light-Resistant Coating System to Protect Dyed Wood from Ultraviolet Irradiation via Layer-by-Layer Self-Assembly. Int J Mol Sci 2022; 23:ijms232415735. [PMID: 36555382 PMCID: PMC9779377 DOI: 10.3390/ijms232415735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Wood dyeing is an effective way to alleviate the supply-demand imbalance of valuable wood and improve the surface decoration of fast-growing wood. However, applications of dyed wood are limited due to the susceptibility of dyes and wood to photo-discolor and degrade under light irradiation. Thus, the improved weather resistance of dyed wood is crucial. To prevent photochromic discoloration of dyed wood, an anti-photochromic coating structure was constructed via layer-by-layer self-assembly (LbL) using chitosan and zinc oxide (ZnO). The results showed that the surface color difference of treated dyed wood was reduced by approximately 84.6% after the first 2 h of irradiation under the following conditions °C: temperature (50 °C), relative humidity (55%), and irradiation intensity (550 W/m2). However, the color of untreated dyed wood drastically changed at this stage. The reason for the decrease was that the redness and yellowness of treated dye wood were significantly reduced. The deposition of ZnO onto treated dyed wood helped to protect the wood from UV light irradiation. Chitosan bridged the dyes and complexed ZnO to enhance UV resistance. This study provides valuable information for the protection of dyed wood against light discoloration that can be used as an interior and exterior decorative material.
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12
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Preparation and Characterization of Water-borne Polyurethane Based on Benzotriazole as Pendant Group with Different N-Alkylated Chain Extenders and Its Application in Anticorrosion. Molecules 2022; 27:molecules27217581. [DOI: 10.3390/molecules27217581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
A series of novel anti-corrosive coatings were synthesized successfully. Water-borne polyurethane (WPU) was synthesized using polyethylene glycol and modified by grafting benzotriazole (BTA) as a pendant group (WPU-g-BTA) and N-alkylated amines (ethylene diamine (A), diethylene triamine (B), triethylene tetramine (C)) as side-chain extenders. Fourier-transform infrared spectroscopy, thermogravimetry, and dynamic mechanical analyses were used to characterize the structural and thermomechanical properties of the samples. A gas permeability analyzer (GPA) was used to evaluate molecular barrier properties. The corrosion inhibition performance of WPU-g-BTA-A, WPU-g-BTA-B, and WPU-g-BTA-C coatings in 3.5 wt% NaCl solution was determined by electrochemical measurements. WPU-g-BTA-C coating synthesized with a high cross-linking density showed superior anticorrosive performance. The as-prepared coatings exhibited a very low icorr value of 0.02 µA.cm−2, a high Ecorr value of −0.02 V, as well as excellent inhibition efficiency (99.972%) and impedance (6.33 Ω) after 30 min of exposure.
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Thermal and photo oxidative degradation of natural rubber film in the presence of iron (III) stearate. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03316-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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14
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Naoom N, Yousif E, Ahmed DS, Kariuki BM, El-Hiti GA. Synthesis of Methyldopa-Tin Complexes and Their Applicability as Photostabilizers for the Protection of Polyvinyl Chloride against Photolysis. Polymers (Basel) 2022; 14:4590. [PMID: 36365583 PMCID: PMC9655565 DOI: 10.3390/polym14214590] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/20/2022] [Accepted: 10/27/2022] [Indexed: 07/30/2023] Open
Abstract
Polyvinyl chloride (PVC) is a ubiquitous thermoplastic that is produced on an enormous industrial scale to meet growing global demand. PVC has many favorable properties and is used in various applications. However, photodecomposition occurs when harsh conditions, such as high temperatures in the presence of oxygen and moisture, are encountered. Thus, PVC is blended with additives to increase its resistance to deterioration caused by exposure to ultraviolet light. In the current research, five methyldopa-tin complexes were synthesized and characterized. The methyldopa-tin complexes were mixed with PVC at a concentration of 0.5% by weight, and thin films were produced. The capability of the complexes to protect PVC from irradiation was shown by a reduction in the formation of small residues containing alcohols, ketones, and alkenes, as well as in weight loss and in the molecular weight of irradiated polymeric blends. In addition, the use of the new additives significantly reduced the roughness factor of the irradiated films. The additives containing aromatic substituents (phenyl rings) were more effective compared to those comprising aliphatic substituents (butyl and methyl groups). Methyldopa-tin complexes have the ability to absorb radiation, coordinate with polymeric chains, and act as radical, peroxide, and hydrogen chloride scavengers.
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Affiliation(s)
- Noor Naoom
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64201, Iraq
| | - Benson M. Kariuki
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Gamal A. El-Hiti
- Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia
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Alvarez-Vega C, Streitwieser DA, Álvarez-Barreto J, Leon-Reyes A. Characterization of low density polyethylene greenhouse films during the composting of rose residues. SN APPLIED SCIENCES 2022. [DOI: 10.1007/s42452-022-05155-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
AbstractThis study presents an evaluation of a potential alternative to plastic degradation in the form of organic composting. It stems from the urgent need of finding solutions to the plastic residues and focuses on the compost-based degradation of greenhouse film covers in an important rose exporter company in Ecuador. Thus, this study analyzes the physical, chemical, and biological changes of rose wastes composting, and also evaluates the stability of new and aged agricultural plastic under these conditions. Interestingly, results of compost characterization show a slow degradation rate of organic matter and total organic carbon, along with a significant increase in pH and rise of bacterial populations. However, the results demonstrate that despite these findings, composting conditions had no significant influence on plastic degradation, and while deterioration of aged plastic samples was reported in some tests, it may be the result of environmental conditions and a prolonged exposure to solar radiation. Importantly, these factors could facilitate the adhesion of microorganisms and promote plastic biodegradation. Hence, it is encouraged for future studies to analyze the ecotoxicity of plastics in the compost, as well as isolate, identify, and evaluate the possible biodegradative potential of these microorganisms as an alternative to plastic waste management.
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Fadhil M, Yousif E, Ahmed DS, Kariuki BM, El-Hiti GA. Synthesis and Application of Levofloxacin–Tin Complexes as New Photostabilizers for Polyvinyl Chloride. Polymers (Basel) 2022; 14:polym14183720. [PMID: 36145863 PMCID: PMC9503127 DOI: 10.3390/polym14183720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/28/2022] Open
Abstract
Polyvinyl chloride (PVC) is a synthetic polymer with a wide range of applications with impact on our daily life. It can undergo photodegradation with toxic products that are hazardous to both human health and the environment. In addition, photodegradation shortens the useful lifetime of the material. Elongation of the effective lifespan of PVC is, therefore, a salient area of research. Recently, a lot of attention has been directed toward the design, preparation, and usage of new additives that are capable of reducing the photodecomposition of PVC. This work investigates the synthesis of new levofloxacin-tin complexes and their potential exploitation against the photodecomposition of PVC. Several levofloxacin-tin complexes have been synthesized, in high yields, by a simple procedure and characterized. The potential use of the additives as photostabilizers for PVC has been investigated through the determination of weight loss, molecular weight depression, formation of fragments containing carbonyl and alkene groups, and surface morphology of irradiated PVC films. The results show that the new additives are effective in reducing the photodegradation of PVC. The new levofloxacin-tin complexes act as absorbers of ultraviolet light and quenchers of highly reactive species such as free radicals produced during photodegradation. They are more effective photostabilizers compared with organotin complexes previously reported. The complexes containing aromatic substituents were more effective than those counterparts having aliphatic residues.
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Affiliation(s)
- Marwa Fadhil
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64201, Iraq
| | - Benson M. Kariuki
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Gamal A. El-Hiti
- Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia
- Correspondence: ; Tel.: +966-11469-3778; Fax: +966-11469-3536
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Mahmudzade R, Nikaeen P, Chirdon W, Khattab A, Depan D. Photodegradation mechanisms and physico-chemical properties of EPON-IPD epoxy-based polymers. REACT FUNCT POLYM 2022. [DOI: 10.1016/j.reactfunctpolym.2022.105351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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18
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Oprea S, Potolinca VO. UV protection by the inclusion of the methoxybenzophenone moieties into the backbone chain of the polyurethane structure. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03230-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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CT-Derived 3D Printing for Coronary Artery Cannulation Simulator Design Manufacturing. Bioengineering (Basel) 2022; 9:bioengineering9080338. [PMID: 35892751 PMCID: PMC9330152 DOI: 10.3390/bioengineering9080338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/06/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022] Open
Abstract
Mastering coronary angiography requires practice. Cadavers and animals do not accurately represent the human anatomical body, and practicing with actual patients has medical safety issues. Simulation offers safe and realistic conditions for cardiology intervention training. In this study, we propose a novel 3D printed simulator that contains physically realistic anatomy and has four access points. It increases safety for patients and students, and production is low-cost. We aimed to make and validate this simulator design as a prototype for coronary cannulation training. It was designed using computed tomography (CT) scan data of aorta, coronary, and heart models, and was printed by 3D printing with resin materials consisting of 75% or 85% clear resin and 25% or 15% flexible resin additive. The simulator was constructed with a camera above the simulator with a degree of LAO of 30°/0°, a display table, and an acrylic box. Twelve validators were interviewed for their expert opinions and analyzed by a qualitative method. They scored the simulator’s suitability on a four-point Likert scale questionnaire. They described the simulator as having admirable values for all aspects (85.8%), curriculum suitability (92%), educational importance (94%), accuracy (83%), efficiency (78%), safety (87.5%), endurance (81.2%), aesthetics (80.7%), storage (85.4%), and affordability (85.8%).
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Synthesis of New Norfloxacin-Tin Complexes to Mitigate the Effect of Ultraviolet-Visible Irradiation in Polyvinyl Chloride Films. Polymers (Basel) 2022; 14:polym14142812. [PMID: 35890588 PMCID: PMC9324004 DOI: 10.3390/polym14142812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 12/03/2022] Open
Abstract
Polyvinyl chloride is used in the manufacturing of a wide range of products, but it is susceptible to degradation if exposed to high temperatures and sunlight. There is therefore a need to continuously explore the design, synthesis, and application of new and improved additives to reduce the photodegradation of polyvinyl chloride in harsh environments and for outdoor applications. This research investigates the use of new norfloxacin–tin complexes as additives to inhibit the photodegradation of polyvinyl chloride to make it last longer. Reactions between norfloxacin and substituted tin chlorides, in different molar ratios and in methanol under reflux conditions, gave the corresponding organotin complexes in high yields. The chemical structures of the synthesized complexes were established, and their effect on the photodegradation of polyvinyl chloride due to ultraviolet-visible irradiation was investigated. Norfloxacin–tin complexes were added to polyvinyl chloride at very low concentrations and homogenous thin films were made. The films were irradiated for a period of up to 300 h, and the damage that occurred was assessed using infrared spectroscopy, polymeric materials weight loss, depression in molecular weight, and surface inspection. The degree of photodegradation in the polymeric materials was much less in the blends containing norfloxacin–tin complexes compared to the case where no additives were used. The use of the additives leads to a reduction in photodegradation (e.g., a reduction in the formation of short-chain polymeric fragments, weight loss, average molecular weight depletion, and roughness factor) of irradiated polyvinyl chloride. The norfloxacin–tin complexes contain aromatic moieties (aryl and heterocycle), heteroatoms (nitrogen, oxygen, and fluorine), and an acidic center (tin atom). Therefore, they act as efficient photostabilizers by absorbing the ultraviolet radiation and scavenging hydrogen chloride, peroxides, and radical species, thereby slowing the photodegradation of polyvinyl chloride.
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Korkmaz Y, Gültekin K. EFFECT OF UV IRRADIATION ON EPOXY ADHESIVES AND ADHESIVELY BONDED JOINTS REINFORCED WITH BN AND B4C NANOPARTICLES. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.110004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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22
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Effects of Ionic Liquid, 1-Ethyl-3-methylimidazolium Chloride ([EMIM]Cl), on the Material and Electrical Characteristics of Asphaltene Thin Films. MATERIALS 2022; 15:ma15082818. [PMID: 35454511 PMCID: PMC9026484 DOI: 10.3390/ma15082818] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 02/07/2023]
Abstract
Asphaltene is a component of crude oil that has remained relatively unexplored for organic electronic applications. In this study, we report on its extraction technique from crude oil tank bottom sludge (COTBS) and its thin-film characteristics when 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) ionic liquid (IL) was introduced as dopants. The extraction technique yielded asphaltene with more than 80% carbon content. The IL resulted in asphaltene thin films with a typical root-mean-square surface roughness of 4 nm, suitable for organic electronic applications. The thin films each showed an optical band gap of 3.8 eV and a sheet resistance as low as 105 Ω/□. When the film was used as a conductive layer in organic field-effect transistors (OFET), it exhibited hole and electron conduction with hole (µh) and electron (µe) mobilities in the order of 10−8 and 10−6 cm2/Vs, respectively. These characteristics are just preliminary in nature. With the right IL, asphaltene thin films may become a good alternative for a transport layer in organic electronic applications.
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Synthesis and Characterization of Epoxy-Rich TMOs Deposited on Stainless Steel for Corrosion Applications. COATINGS 2022. [DOI: 10.3390/coatings12030387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Epoxy-trimetallic oxide (epoxy-TMO) coatings of ZrO2:TiO2:ZnO at different compositions were synthesized and used to protect a stainless steel surface. The different TMO compositions were synthesized using the ball-milling method and later dispersed on the polymer matrix. The different characterizations performed on these coatings showed that the epoxy-TMO coating with a ratio of 50:40:10 (wt%) exhibited the highest corrosion resistance, in the order of ~1012 Ωcm2, due to the barrier effect of the distributed particles after 28 days in an aggressive environment (3.5 wt% NaCl solution). The influence of the metal oxides in forming a semiconductor layer produces a capacitor-like behavior, influencing corrosion control via a mass transfer mechanism barrier. The water uptake reveals the effect of each metal oxide in the formation of a physical barrier due to the dispersion mechanism, as well as how the particles function within the polymer matrix.
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Fabrication of Highly Photostable Polystyrene Films Embedded with Organometallic Complexes. Polymers (Basel) 2022; 14:polym14051024. [PMID: 35267847 PMCID: PMC8914741 DOI: 10.3390/polym14051024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/26/2022] [Accepted: 03/02/2022] [Indexed: 02/01/2023] Open
Abstract
Polystyrene is a common thermoplastic and is produced in different shapes and forms. The scale of manufacture of polystyrene has grown over the years because of its numerous applications and low cost of production. However, it is flammable, brittle, has low resistance to chemicals, and is susceptible to photodegradation on exposure to ultraviolet radiation. There is therefore scope to improve the properties of polystyrene and to extend its useful lifetime. The current work reports the synthesis of organometallic complexes and investigates their use as photostabilizers for polystyrene. The reaction of excess ibuprofen sodium salt and appropriate metal chlorides in boiling methanol gave the corresponding complexes excellent yields. The organometallic complexes (0.5% by weight) were added to polystyrene and homogenous thin films were made. The polystyrene films blended with metal complexes were irradiated with ultraviolet light for extended periods of time and the stabilizing effects of the additives were assessed. The infrared spectroscopy, weight loss, depression in molecular weight, and surface morphology of the irradiated blends containing organometallic complexes were investigated. All the synthesized organometallic complexes acted as photostabilizers for polystyrene. The damage (e.g., formation of small polymeric fragments, decrease in weight and molecular weight, and irregularities in the surface) that took place in the polystyrene blends was much lower in comparison to the pure polystyrene film. The manganese-containing complex was very effective in stabilizing polystyrene and was superior to cobalt and nickel complexes.
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Islas S, Cuéllar-Cruz M. Silica-Carbonate of Ba(II) and Fe 2+/Fe 3+ Complex as Study Models to Understand Prebiotic Chemistry. ACS OMEGA 2021; 6:35629-35640. [PMID: 34984294 PMCID: PMC8717530 DOI: 10.1021/acsomega.1c05415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/01/2021] [Indexed: 06/14/2023]
Abstract
The Precambrian era is called the first stage of the Earth history and is considered the longest stage in the geological time scale. Despite its duration, several of its environmental and chemical characteristics are still being studied. It is an era of special relevance not only for its duration but also because it is when a set of conditions gave rise to the first organism. This pioneer organism has been proposed to have been formed by a mineral and an organic part. A chemical element suggested to have been part of the structure of this cell is iron. However, what special characteristic does iron have with respect to other chemical elements to be proposed as part of this first cell? To answer this and other questions, it is indispensable to have a model that will allow extrapolating the first chemical structures of the pioneer organism formed in the Precambrian. In this context, for several decades, in vitro structures chemically formed by silica-carbonates have been synthetized, called biomorphs, because they could emulate living organisms and might resemble primitive organisms. It has been inferred that because biomorphs form structures with characteristic morphologies, they could resemble the microfossils found in the cherts of the Precambrian. Aiming at providing some insight on how iron contributed to the formation of the chemical structures of the primitive organism, we evaluated how iron contributes to the morphology and chemical-crystalline structure during the synthesis of these compounds under different conditions found in the primitive atmosphere. Experimentally, synthesis of biomorphs was performed at four different atmospheric conditions including UV light, nonionizing microwave radiation (NIR-mw), water steam (WS), and CO2 in the presence of Fe2+, Fe3+, and Fe2+/Fe3+, obtaining 48 different conditions. The produced biomorphs were observed under scanning electron microscopy (SEM). Afterward, their chemical composition and crystalline structure were analyzed through Raman and IR spectroscopy.
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Affiliation(s)
- Selene
R. Islas
- Instituto
de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Ciudad de México 04510, México
| | - Mayra Cuéllar-Cruz
- Departamento
de Biología, División de Ciencias Naturales y Exactas,
Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, Col. Noria Alta, C.P. 36050 Guanajuato, Guanajuato, México
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El-Hiti GA, Ahmed DS, Yousif E, Al-Khazrajy OSA, Abdallh M, Alanazi SA. Modifications of Polymers through the Addition of Ultraviolet Absorbers to Reduce the Aging Effect of Accelerated and Natural Irradiation. Polymers (Basel) 2021; 14:20. [PMID: 35012042 PMCID: PMC8747282 DOI: 10.3390/polym14010020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022] Open
Abstract
The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of safe, plastic, ultraviolet stabilizers that do not pose a danger to the environment if released. Plastic ultraviolet photostabilizers act as efficient light screeners (absorbers or pigments), excited-state deactivators (quenchers), hydroperoxide decomposers, and radical scavengers. Ultraviolet absorbers are cheap to produce, can be used in low concentrations, mix well with polymers to produce a homogenous matrix, and do not alter the color of polymers. Recently, polyphosphates, Schiff bases, and organometallic complexes were synthesized and used as potential ultraviolet absorbers for polymeric materials. They reduced the damage caused by accelerated and natural ultraviolet aging, which was confirmed by inspecting the surface morphology of irradiated polymeric films. For example, atomic force microscopy revealed that the roughness factor of polymers' irradiated surfaces was improved significantly in the presence of ultraviolet absorbers. In addition, the investigation of the surface of irradiated polymers using scanning electron microscopy showed a high degree of homogeneity and the appearance of pores that were different in size and shape. The current work surveys for the first time the use of newly synthesized, ultraviolet absorbers as additives to enhance the photostability of polymeric materials and, in particular, polyvinyl chloride and polystyrene, based mainly on our own recent work in the field.
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Affiliation(s)
- Gamal A. El-Hiti
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia;
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64021, Iraq;
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq; (E.Y.); (M.A.)
| | - Omar S. A. Al-Khazrajy
- Department of Chemistry, College of Education for Pure Science (Ibn Al-Haytham), University of Baghdad, Baghdad 64021, Iraq;
| | - Mustafa Abdallh
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq; (E.Y.); (M.A.)
| | - Saud A. Alanazi
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia;
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Alhaydary E, Yousif E, Al-Mashhadani MH, Ahmed DS, Jawad AH, Bufaroosha M, Ahmed AA. Sulfamethoxazole as a ligand to synthesize di- and tri-alkyltin(IV) complexes and using as excellent photo-stabilizers for PVC. JOURNAL OF POLYMER RESEARCH 2021. [DOI: 10.1007/s10965-021-02822-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Tin(IV) Compounds as Photo-Stabilizers for Irradiated Surfaces of Poly(Vinyl Chloride) Films. SURFACES 2021. [DOI: 10.3390/surfaces4040023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dimethyl-organotin(IV) valsartan (Me2SnL2) and dichlorostannanediyl valsartan (SnL2Cl2) complexes were synthesized, characterized, and applied as Poly(vinyl chloride) (PVC) photo-stabilizers. The complexes were loaded within the PVC films in a weight ratio of 0.5%, and the modified films were irradiated to a UV light of 313 nm wavelength for 300 h at room temperature. The efficiency of the complexes-filled films was compared with the plain one and evaluated before and after irradiation by Fourier transform infrared spectroscopy, weight loss, gel content, change in viscosity, atomic force microscopy, and field emission scanning electron microscopy. The SnL2Cl2 complex had higher activity than the Me2SnL2 complex to retard the PVC’s photodegradation by several mechanisms.
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He Y, Fan D, Chen J, Zhao J, Kong M, Lv Y, Huang Y, Li G. Multiple stabilization roles of thermally reduced graphene oxide for both thermo‐ and photo‐oxidation of polypropylene: deter, delay, and defend. POLYM ADVAN TECHNOL 2021. [DOI: 10.1002/pat.5532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yusong He
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Daiqi Fan
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Jiaxing Chen
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Jincan Zhao
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Miqiu Kong
- School of Aeronautics and Astronautics, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Yadong Lv
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Yajiang Huang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
| | - Guangxian Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China Sichuan University Chengdu China
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Yaseen AA, Yousif E, Al-Tikrity ETB, El-Hiti GA, Kariuki BM, Ahmed DS, Bufaroosha M. FTIR, Weight, and Surface Morphology of Poly(vinyl chloride) Doped with Tin Complexes Containing Aromatic and Heterocyclic Moieties. Polymers (Basel) 2021; 13:polym13193264. [PMID: 34641080 PMCID: PMC8512238 DOI: 10.3390/polym13193264] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 01/20/2023] Open
Abstract
Poly(vinyl chloride) (PVC) is an important synthetic plastic that is produced in large quantities (millions of tons) annually. Additives to PVC are necessary to allow its use in many applications, particularly in harsh conditions. In regard to this, investigation of the synthesis of trimethoprim–tin complexes and their use as PVC additives is reported. Trimethoprim–tin complexes were obtained from the reaction of trimethoprim and tin chlorides using simple procedures. Trimethoprim–tin complexes (0.5% by weight) were added to PVC to produce homogenous mixtures and thin films were made. The effect of ultraviolet irradiation on the surface and properties of the PVC films was investigated. The level of both photodecomposition and photo-oxidation of PVC films containing trimethoprim–tin complexes was observed to be lower than for the blank film. The effectiveness of tin complexes as PVC photostabilizers reflects the aromaticity of the additives. The complex containing three phenyl groups attached to the tin cation showed the most stabilizing effect on PVC. The complex containing two phenyl groups was next, with the one containing butyl substituents resulting in the least stabilization of PVC. A number of mechanisms have been proposed to explain the role of the synthesized complexes in PVC photostabilization.
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Affiliation(s)
- Anaheed A. Yaseen
- Department of Chemistry, College of Science, Tikrit University, Tikrit 34001, Iraq; (A.A.Y.); (E.T.B.A.-T.)
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq;
| | - Emaad T. B. Al-Tikrity
- Department of Chemistry, College of Science, Tikrit University, Tikrit 34001, Iraq; (A.A.Y.); (E.T.B.A.-T.)
| | - Gamal A. El-Hiti
- Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia
- Correspondence: ; Tel.: +966-11469-3778; Fax: +966-11469-3536
| | - Benson M. Kariuki
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK;
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64021, Iraq;
| | - Muna Bufaroosha
- Department of Chemistry, College of Science, United Arab Emirates University, P.O. Box 15551, Al-Ain 1818, United Arab Emirates;
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Yaseen AA, Al-Tikrity ETB, Yousif E, Ahmed DS, Kariuki BM, El-Hiti GA. Effect of Ultraviolet Irradiation on Polystyrene Containing Cephalexin Schiff Bases. Polymers (Basel) 2021; 13:polym13172982. [PMID: 34503022 PMCID: PMC8434342 DOI: 10.3390/polym13172982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
The scale of production of polystyrene has escalated in the recent past in order to meet growing demand. As a result, a large quantity of polystyrene waste continues to be generated along with associated health and environmental problems. One way to tackle such problems is to lengthen the lifetime of polystyrene, especially for outdoor applications. Our approach is the synthesis and application of new ultraviolet photostabilizers for polystyrene and this research is focused on four cephalexin Schiff bases. The reaction of cephalexin and 3-hydroxybenzaldehyde, 4-dimethylaminobenzaldehyde, 4-methoxybenzaldehyde, and 4-bromobanzaldehyde under acidic condition afforded the corresponding Schiff bases in high yields. The Schiff bases were characterized and their surfaces were examined. The Schiff bases were mixed with polystyrene to form homogenous blends and their effectiveness as photostabilizers was explored using different methods. The methods included monitoring the changes in the infrared spectra, weight loss, depression in molecular weight, and surface morphology on irradiation. In the presence of the Schiff bases, the formation of carbonyl group fragments, weight loss, and decrease in molecular weight of polystyrene were lower when compared with pure polystyrene. In addition, undesirable changes in the surface such as the appearance of dark spots, cracks, and roughness were minimal for irradiated polystyrene containing cephalexin Schiff bases. Mechanisms by which cephalexin Schiff bases stabilize polystyrene against photodegradation have also been suggested.
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Affiliation(s)
- Anaheed A. Yaseen
- Department of Chemistry, College of Science, Tikrit University, Tikrit 34001, Iraq; (A.A.Y.); (E.T.B.A.-T.)
| | - Emaad T. B. Al-Tikrity
- Department of Chemistry, College of Science, Tikrit University, Tikrit 34001, Iraq; (A.A.Y.); (E.T.B.A.-T.)
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq;
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64021, Iraq;
| | - Benson M. Kariuki
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK;
| | - Gamal A. El-Hiti
- Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia
- Correspondence: ; Tel.: +966-11469-3778; Fax: +966-11469-3536
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Acoustic Emission Testing and Ib-Value Analysis of Ultraviolet Light-Irradiated Fiber Composites. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11146550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The failure behavior of composites under ultraviolet (UV) irradiation was investigated by acoustic emission (AE) testing and Ib-value analysis. AE signals were acquired from woven glass fiber/epoxy specimens tested under tensile load. Cracks initiated earlier in UV-irradiated specimens, with a higher crack growth rate in comparison to the pristine specimen. In the UV-degraded specimen, a serrated fracture surface appeared due to surface hardening and damaged interfaces. All specimens displayed a linearly decreasing trend in Ib-values with an increasing irradiation time, reaching the same value at final failure even when the starting values were different.
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Migration of monomers, plastic additives, and non-intentionally added substances from food utensils made of melamine–formaldehyde resin following ultraviolet sterilization. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107981] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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34
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An Experimental Study on the Dynamic Mechanical Properties of Epoxy Polymer Concrete under Ultraviolet Aging. MATERIALS 2021; 14:ma14082074. [PMID: 33924102 PMCID: PMC8074335 DOI: 10.3390/ma14082074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/15/2021] [Accepted: 04/18/2021] [Indexed: 11/16/2022]
Abstract
Epoxy polymer concrete (EPC) is widely applied in engineering for its excellent mechanical properties. The impact loads and severe climatic conditions such as ultraviolet radiation, temperature change and rain erosion are in general for its engineering practice, potentially degrading the performance of EPC. In this paper, a procedure of accelerated aging for EPC, imitating the aging effect of ultraviolet radiation and hygrothermal conditions based on the meteorological statistics of Guangzhou city, was designed. After various periods of accelerated aging, the dynamic behaviors of EPC were studied by using a Split Hopkinson Pressure Bar (SHPB). The verification of the experimental data was performed. The two-stage dynamic compression stress-strain curves were obtained: (a) linear growth stage following by strain hardening stage at impact velocity 12.2 m/s and 18.8 m/s, (b) linear growth stage and then a horizontal stage when impact velocity is 25.0 m/s, (c) linear growth stage following by strain softening stage at impact velocity 29.2 m/s. The experimental results show that the specimens after longer accelerated aging tend to be more easily broken, especially at impact velocity 12.2 m/s and 18.8 m/s, while the strain rate is the main factor affecting the compression strength and stiffness. Ultimately the influence of strain rate and equivalent aging time on dynamic increase factor was revealed by a fitting surface.
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Photostabilization of Poly(vinyl chloride) Films Blended with Organotin Complexes of Mefenamic Acid for Outdoor Applications. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11062853] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study develops a process for enhancing the photostabilization of PVC films blended with a low concentration of mefenamate–tin complex. One tri-substituted and three di-substituted organotin complexes containing mefenamate unit are synthesized, and their chemical structures are established. The reactions of mefenamic acid and a number of substituted tin chlorides gave the corresponding tin complexes in 70–77% yields. Tin complexes were blended with PVC and thin films. The effect of the addition of additives against long-term irradiation (290–400 nm, 300 h) is also tested. Changes in the infrared spectra, weight, and surface of the PVC blends due to irradiation are examined and analyzed. Any damage to the PVC surface and its chemical degradation level are noticeably low in the presence of additives. Minimal photodegradation levels and surface changes of the irradiated PVC films are observed when the triphenyltin complex is used. Such a complex is highly aromatic and can act as an ultraviolet irradiation absorber and a scavenger for hydrogen chloride and radicals produced due to the photooxidation and photoirradiation of PVC films.
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Omer RM, Al-Tikrity ETB, Yousif E, El-Hiti GA, Ahmed DS, Ahmed AA. Spectroscopic and Morphological Study of Irradiated PVC Films Doped with Polyphosphates Containing 4,4'-Methylenedianiline. RUSS J APPL CHEM+ 2021. [DOI: 10.1134/s1070427220120113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Liu J, Ma X, Shi W, Xing J, Ma C, Li S, Huang Y. Ultraviolet blocking and antioxidant polyvinyl alcohol films incorporated with baicalin extraction from Scutellaria baicalensis Georgi. JOURNAL OF POLYMER ENGINEERING 2021. [DOI: 10.1515/polyeng-2020-0071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.
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Affiliation(s)
- Jinshu Liu
- Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Key Laboratory of Polymer Science and Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University , Xi’an 710129 , Shaanxi Province, China
- College of Textile Science and Engineering, Xi’an Polytechnic University , Xi’an 710048 , China
| | - Xiaoyan Ma
- Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Key Laboratory of Polymer Science and Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University , Xi’an 710129 , Shaanxi Province, China
| | - Wenzhao Shi
- College of Textile Science and Engineering, Xi’an Polytechnic University , Xi’an 710048 , China
| | - Jianwei Xing
- College of Textile Science and Engineering, Xi’an Polytechnic University , Xi’an 710048 , China
| | - Chaoqun Ma
- College of Textile Science and Engineering, Xi’an Polytechnic University , Xi’an 710048 , China
| | - Susong Li
- College of Textile Science and Engineering, Xi’an Polytechnic University , Xi’an 710048 , China
| | - Yayi Huang
- College of Textile Science and Engineering, Xi’an Polytechnic University , Xi’an 710048 , China
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Synthesis of Carvedilol-Organotin Complexes and Their Effects on Reducing Photodegradation of Poly(Vinyl Chloride). Polymers (Basel) 2021; 13:polym13040500. [PMID: 33561971 PMCID: PMC7915541 DOI: 10.3390/polym13040500] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/21/2021] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
Poly(vinyl chloride) (PVC) undergoes photodegradation induced by ultraviolet (UV) irradiation; therefore, for outdoor applications, its photostability should be enhanced through the use of additives. Several carvedilol tin complexes were synthesized, characterized and mixed with PVC to produce thin films. These films were irradiated at 25 °C with a UV light (λ = 313 nm) for up to 300 h. The reduction in weight and changes in chemical structure and surface morphology of the PVC films were monitored. The films containing synthesized complexes showed less undesirable changes than the pure PVC film. Organotin with a high content of aromatics was particularly efficient in inhibiting photodegradation of PVC. The carvedilol tin complexes both absorbed UV light and scavenged radicals, hydrochloride, and peroxides and, therefore, photostabilized PVC.
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A Review on Graphene’s Light Stabilizing Effects for Reduced Photodegradation of Polymers. CRYSTALS 2020. [DOI: 10.3390/cryst11010003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Graphene, the newest member of the carbon’s family, has proven its efficiency in improving polymers’ resistance against photodegradation, even at low loadings equal to 1 wt% or lower. This protective role involves a multitude of complementary mechanisms associated with graphene’s unique geometry and chemistry. In this review, these mechanisms, taking place during both the initiation and propagation steps of photodegradation, are discussed concerning graphene and graphene derivatives, i.e., graphene oxide (GO) and reduced graphene oxide (rGO). In particular, graphene displays important UV absorption, free radical scavenging, and quenching capabilities thanks to the abundant π-bonds and sp2 carbon sites in its hexagonal lattice structure. The free radical scavenging effect is also partially linked with functional hydroxyl groups on the surface. However, the sp2 sites remain the predominant player, which makes graphene’s antioxidant effect potentially stronger than rGO and GO. Besides, UV screening and oxygen barriers are active protective mechanisms attributed to graphene’s high surface area and 2D geometry. Moreover, the way that graphene, as a nucleating agent, can improve the photostability of polymers, have been explored as well. These include the potential effect of graphene on increasing polymer’s glass transition temperature and crystallinity.
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Salam B, El-Hiti GA, Bufaroosha M, Ahmed DS, Ahmed A, Alotaibi MH, Yousif E. Tin Complexes Containing an Atenolol Moiety as Photostabilizers for Poly(Vinyl Chloride). Polymers (Basel) 2020; 12:polym12122923. [PMID: 33291282 PMCID: PMC7768508 DOI: 10.3390/polym12122923] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 11/17/2022] Open
Abstract
The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.
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Affiliation(s)
- Baneen Salam
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq;
| | - Gamal A. El-Hiti
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia
- Correspondence: (G.A.E.-H.); (M.H.A.); (E.Y.); Tel.: +966-11469-3778 (G.A.E.-H.); Fax: +966-11469-3536 (G.A.E.-H.)
| | - Muna Bufaroosha
- Department of Chemistry, College of Science, United Arab Emirates University, P.O. Box 15551, Al-Ain 1818, UAE;
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64021, Iraq;
| | - Ahmed Ahmed
- Polymer Research Unit, College of Science, Al-Mustansiriyah University, Baghdad 10052, Iraq;
| | - Mohammad Hayal Alotaibi
- National Center for Petrochemicals Technology, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442, Saudi Arabia
- Correspondence: (G.A.E.-H.); (M.H.A.); (E.Y.); Tel.: +966-11469-3778 (G.A.E.-H.); Fax: +966-11469-3536 (G.A.E.-H.)
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq;
- Correspondence: (G.A.E.-H.); (M.H.A.); (E.Y.); Tel.: +966-11469-3778 (G.A.E.-H.); Fax: +966-11469-3536 (G.A.E.-H.)
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Khotbehsara MM, Manalo A, Aravinthan T, Turner J, Ferdous W, Hota G. Effects of ultraviolet solar radiation on the properties of particulate-filled epoxy based polymer coating. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109352] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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42
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Lesiak P, Bednarska K, Małkowski K, Kozłowski Ł, Wróblewska A, Sobotka P, Dydek K, Boczkowska A, Osuch T, Anuszkiewicz A, Lewoczko-Adamczyk W, Schröder H, Woliński TR. UV Sensor Based on Fiber Bragg Grating Covered with Graphene Oxide Embedded in Composite Materials. SENSORS (BASEL, SWITZERLAND) 2020; 20:s20195468. [PMID: 32987696 PMCID: PMC7584041 DOI: 10.3390/s20195468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
Polymer-matrix composites degrade under the influence of UV radiation in the range of the 290-400 nm band. The degradation of polymer-matrix composites exposed to UV radiation is characterized by extensive aging of the epoxy matrix, resulting in deterioration of their mechanical properties. Glass fibers/epoxy resin composites were made by an out-of-autoclave method whereas a fiber optic sensor was placed between different layers of laminates. In our work, we used a fiber Bragg grating sensor covered with graphene oxide and embedded in a polymer matrix composite to monitor UV radiation intensity. Measurements of UV radiation may allow monitoring the aging process of individual components of the polymer composite. In order to estimate the number of microcracks of epoxy resin, microstructure observations were carried out using a scanning electron microscope.
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Affiliation(s)
- Piotr Lesiak
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
| | - Karolina Bednarska
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
- Centre for Advanced Materials and Technologies CEZAMAT, 02-822 Warszawa, Poland
| | - Krzysztof Małkowski
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
| | - Łukasz Kozłowski
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
| | - Anna Wróblewska
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
| | - Piotr Sobotka
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
| | - Kamil Dydek
- Faculty of Materials Science and Engineering, Warsaw University of Technology, 02-507 Warszawa, Poland; (K.D.); (A.B.)
| | - Anna Boczkowska
- Faculty of Materials Science and Engineering, Warsaw University of Technology, 02-507 Warszawa, Poland; (K.D.); (A.B.)
| | - Tomasz Osuch
- Faculty of Electronics and Information Technology, Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warszawa, Poland; (T.O.); (A.A.)
| | - Alicja Anuszkiewicz
- Faculty of Electronics and Information Technology, Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warszawa, Poland; (T.O.); (A.A.)
| | - Wojciech Lewoczko-Adamczyk
- Abt. SIIT/Optical Interconnection Technology, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (IZM), 13355 Berlin, Germany; (W.L.-A.); (H.S.)
| | - Henning Schröder
- Abt. SIIT/Optical Interconnection Technology, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (IZM), 13355 Berlin, Germany; (W.L.-A.); (H.S.)
| | - Tomasz Ryszard Woliński
- Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa, Poland; (K.B.); (K.M.); (Ł.K.); (A.W.); (P.S.); (T.R.W.)
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Mahmood ZN, Yousif E, Alias M, El-Hiti GA, Ahmed DS. Synthesis, characterization, properties, and use of new fusidate organotin complexes as additives to inhibit poly(vinyl chloride) photodegradation. JOURNAL OF POLYMER RESEARCH 2020. [DOI: 10.1007/s10965-020-02245-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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44
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Fromel M, Li M, Pester CW. Surface Engineering with Polymer Brush Photolithography. Macromol Rapid Commun 2020; 41:e2000177. [DOI: 10.1002/marc.202000177] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/28/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Michele Fromel
- Department of Chemical Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Mingxiao Li
- Department of Chemical Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Christian W. Pester
- Department of Chemical Engineering The Pennsylvania State University University Park PA 16802 USA
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
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Mohammed A, El-Hiti GA, Yousif E, Ahmed AA, Ahmed DS, Alotaibi MH. Protection of Poly(Vinyl Chloride) Films against Photodegradation Using Various Valsartan Tin Complexes. Polymers (Basel) 2020; 12:polym12040969. [PMID: 32326307 PMCID: PMC7240378 DOI: 10.3390/polym12040969] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 01/02/2023] Open
Abstract
Poly(vinyl chloride) is a common plastic that is widely used in many industrial applications. Poly(vinyl chloride) is mixed with additives to improve its mechanical and physical properties and to enable its use in harsh environments. Herein, to protect poly(vinyl chloride) films against photoirradiation with ultraviolet light, a number of tin complexes containing valsartan were synthesized and their chemical structures were established. Fourier-transform infrared spectroscopy, weight loss, and molecular weight determination showed that the non-desirable changes were lower in the films containing the tin complexes than for the blank polymeric films. Analysis of the surface morphology of the irradiated polymeric materials showed that the films containing additives were less rough than the irradiated blank film. The tin complexes protected the poly(vinyl chloride) films against irradiation, where the complexes with high aromaticity were particularly effective. The additives act as primary and secondary stabilizers that absorb the incident radiation and slowly remit it to the polymeric chain as heat energy over time at a harmless level.
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Affiliation(s)
- Alaa Mohammed
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq;
| | - Gamal A. El-Hiti
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia
- Correspondence: (G.A.E.-H.); (E.Y.); (M.H.A.); Tel.: +966-11469-3778 (G.A.E.-H.); Fax: +966-11469-3536 (G.A.E.-H.)
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq;
- Correspondence: (G.A.E.-H.); (E.Y.); (M.H.A.); Tel.: +966-11469-3778 (G.A.E.-H.); Fax: +966-11469-3536 (G.A.E.-H.)
| | - Ahmed A. Ahmed
- Polymer Research Unit, College of Science, Al-Mustansiriyah University, Baghdad 10052, Iraq;
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64021, Iraq;
| | - Mohammad Hayal Alotaibi
- National Center for Petrochemicals Technology, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442, Saudi Arabia
- Correspondence: (G.A.E.-H.); (E.Y.); (M.H.A.); Tel.: +966-11469-3778 (G.A.E.-H.); Fax: +966-11469-3536 (G.A.E.-H.)
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Surface cleaning and sample carrier for complementary high-resolution imaging techniques. Biointerphases 2020; 15:021005. [PMID: 32212739 DOI: 10.1116/1.5143203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Nowadays, high-resolution imaging techniques are extensively applied in a complementary way to gain insights into complex phenomena. For a truly complementary analytical approach, a common sample carrier is required that is suitable for the different preparation methods necessary for each analytical technique. This sample carrier should be capable of accommodating diverse analytes and maintaining their pristine composition and arrangement during deposition and preparation. In this work, a new type of sample carrier consisting of a silicon wafer with a hydrophilic polymer coating was developed. The robustness of the polymer coating toward solvents was strengthened by cross-linking and stoving. Furthermore, a new method of UV-ozone cleaning was developed that enhances the adhesion of the polymer coating to the wafer and ensures reproducible surface-properties of the resulting sample carrier. The hydrophilicity of the sample carrier was recovered applying the new method of UV-ozone cleaning, while avoiding UV-induced damages to the polymer. Noncontact 3D optical profilometry and contact angle measurements were used to monitor the hydrophilicity of the coating. The hydrophilicity of the polymer coating ensures its spongelike behavior so that upon the deposition of an analyte suspension, the solvent and solutes are separated from the analyte by absorption into the polymer. This feature is essential to limit the coffee-ring effect and preserve the native identity of an analyte upon deposition. The suitability of the sample carrier for various sample types was tested using nanoparticles from suspension, bacterial cells, and tissue sections. To assess the homogeneity of the analyte distribution and preservation of sample integrity, optical and scanning electron microscopy, helium ion microscopy, laser ablation inductively coupled plasma mass spectrometry, and time-of-flight secondary ion mass spectrometry were used. This demonstrates the broad applicability of the newly developed sample carrier and its value for complementary imaging.
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Huang M, Liu Y, Klier J, Schiffman JD. High-Performance, UV-Curable Crosslinked Films via Grafting of Hydroxyethyl Methacrylate Methylene Malonate. Ind Eng Chem Res 2020; 59:4542-4548. [PMID: 34045792 DOI: 10.1021/acs.iecr.9b06618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermoset coatings have been used extensively to protect and enhance the appearance of substrates for industrial maintenance and architectural applications. Here, we demonstrate that anionic polymerization can be used to first graft hydroxyethyl methacrylate methylene malonate (HEMA-MM) onto a latex particle at ambient conditions, while subsequent ultraviolet (UV) exposure enabled their crosslinking into robust coatings. At room temperature, in the presence of air and water, the polymerization of HEMA-MM was initiated by anionic carboxyl groups present on the MAA latex particles and subsequently grafted onto the surface of particles. The pendent hydroxyethyl methacrylate (HEMA) group enabled UV-curing via free radical polymerization and the formation of a crosslinked network. Systematic investigations were conducted to study the formation and performance of the crosslinked coatings as a function of HEMA-MM incorporation. The incorporation of 10 wt% HEMA-MM into MAA latex yielded crosslinked coatings with decreased swelling, a heightened glass transition temperature (by ~20 °C) and a 2.9-fold improvement in the Young's moduli compared to controls (without HEMA-MM). Here, we demonstrate a facile method that provides a one-step grafting-functionalization approach using functional methylene malonates to produce UV-curable and high-performance coatings at room temperature and under atmospheric environments.
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Affiliation(s)
- Mengfei Huang
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States
| | - Yuan Liu
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States
| | - John Klier
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States
| | - Jessica D Schiffman
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States
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Ovodok E, Maltanava H, Poznyak S, Ivanovskaya M, Shendyukov V, Spacek V, Scharnagl N, Maia F, Tedim J. Rhodamine-loaded TiO2 particles for detection of polymer coating UV degradation. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.matpr.2019.10.069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Patti A, Acierno D. The Puncture and Water Resistance of Polyurethane- Impregnated Fabrics after UV Weathering. Polymers (Basel) 2019; 12:polym12010015. [PMID: 31861662 PMCID: PMC7022708 DOI: 10.3390/polym12010015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/13/2019] [Accepted: 12/16/2019] [Indexed: 11/16/2022] Open
Abstract
Polyurethane is a polymer adaptable to different scientific and industrial requirements; nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment; but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.
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Affiliation(s)
- Antonella Patti
- Department of Civil Engineering and Architecture, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy;
| | - Domenico Acierno
- CRdC Nuove Tecnologie per le Attività Produttive Scarl, Via Nuova Agnano 11, 80125 Naples, Italy
- Correspondence:
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Ma D, Pan Z, Liu Y, Jiang Z, Liu Z, Zhou L, Tang L. Residual Flexural Performance of Epoxy Polymer Concrete under Hygrothermal Conditions and Ultraviolet Aging. MATERIALS 2019; 12:ma12213472. [PMID: 31652706 PMCID: PMC6862287 DOI: 10.3390/ma12213472] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/17/2019] [Accepted: 10/20/2019] [Indexed: 11/19/2022]
Abstract
Epoxy polymer concrete (EPC) has found increasing applications in infrastructure as a rising candidate among civil engineering materials. In most of its service environments, EPC is inevitably exposed to severe weather conditions, e.g., violent changes in temperature, rain, and ultraviolet (UV) radiation. In this paper, we designed an accelerated aging test for EPC, which includes periodic variation of temperature and water spray, as well as intensive UV-light irradiation, imitating the outdoor environment in South China. The experimental results show that the flexural performance of EPC is found deteriorate with the aging time. An aging process equivalent to four years (UV radiation dose) results in up to 8.4% reduction of flexural strength. To explore the mechanisms of observed performance degradation, the EPC specimen in the four-point-bending test is considered as a layered beam. The analysis indicates that the loss of flexural load-carrying capacity of an aged EPC beam is dominated by the reduction of mechanical properties of the surface layer. The mechanical properties of the surface layer are closely associated with the aging of epoxy mortar, which can be approximated as a reciprocal function of the aging time. By introducing damage to the surface layer into the layered beam, the proposed model demonstrates a good ability to predict the residual flexural strength of EPC during the aging process
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Affiliation(s)
- Dongpeng Ma
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Zhiwei Pan
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Yiping Liu
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Zhenyu Jiang
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Zejia Liu
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Licheng Zhou
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Liqun Tang
- State Key Laboratory of Subtropical Building Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
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