1
|
Enhancement of 3D Printability by FDM and Electrical Conductivity of PLA/MWCNT Filaments Using Lignin as Bio-Dispersant. Polymers (Basel) 2023; 15:polym15040999. [PMID: 36850283 PMCID: PMC9960198 DOI: 10.3390/polym15040999] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
To increase the applications of FDM (fusion deposition modeling) 3D printing in electronics, it is necessary to develop new filaments with good electrical properties and suitable processability. In this work, polymer composites filament-shaped with superior electrical performance based on polylactic acid (PLA) carbon nanotubes and lignin blends have been studied by combining solution mixing and melt blending. The results showed that composites achieve electrical percolation from 5 wt.% of nanotubes, with high electrical conductivity. Moreover, the introduction of a plasticizing additive, lignin, improved the printability of the material while increasing its electrical conductivity (from (1.5 ± 0.9)·10-7 S·cm-1 to (1.4 ± 0.9)·10-1 S cm-1 with 5 wt.% carbon nanotubes and 1 wt.% lignin) maintaining the mechanical properties of composite without additive. To validate lignin performance, its effect on PLA/MWCNT was compare with polyethylene glycol. PEG is a well-known commercial additive, and its use as dispersant and plasticizer in PLA/MWCNT composites has been proven in bibliography. PLA/MWCNT composites display easier processability by 3D printing and more adhesion between the printed layers with lignin than with PEG. In addition, the polyethylene glycol produces a plasticizing effect in the PLA matrix reducing the composite stiffness. Finally, an interactive electronic prototype was 3D printed to assess the printability of the new conducting filaments with 5 wt.% of MWCNT.
Collapse
|
2
|
The Use of Nanoscale Montmorillonite (MMT) as Reinforcement for Polylactide Acid (PLA) Prepared by Fused Deposition Modeling (FDM)—Comparative Study with Biocarbon and Talc Fillers. MATERIALS 2022; 15:ma15155205. [PMID: 35955140 PMCID: PMC9369621 DOI: 10.3390/ma15155205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/19/2022] [Accepted: 07/23/2022] [Indexed: 11/16/2022]
Abstract
The subject of the presented research focuses on a comparative assessment of three types of polymer fillers used to modify highly crystalline poly(lactic acid) PLA intended for the FDM technique. The aim of the presented work was to determine the performance of the developed materials. The key aspect of the work was the use of polymer fillers of three different types. Nano-sized montmorillonite (MMT), biobased biocarbon (BC) and mineral talc. The several types of composites were prepared using extrusion technique. The maximum content for BC and talc filler was limited to 20 wt%, while for MMT it was 5 wt%. Prepared samples were subjected to detailed material analysis including mechanical tests (tensile, flexural, Charpy), thermal analysis (DSC, DMTA), HDT/Vicat tests and structure analysis. The results of the test confirmed that even relatively small amount of nano-type filler can be more efficient than micrometric particles. The used type of matrix was highly crystalline PLA, which resulted in a significant nucleation effect of the crystalline structure. However, thermomechanical tests revealed no improvement in thermal resistance. Microscopic survey confirmed that for MMT and talc filler the structure anisotropy was leading to more favorable properties, especially when compared to structures based on spherical BC particles.
Collapse
|
3
|
Jongpanya-Ngam P, Khankrua R, Seadan M, Suttiruengwong S. Effect of synthesized sulfonate derivatives as nucleating agents on crystallization behavior of poly(lactic acid). Des Monomers Polym 2022; 25:115-127. [PMID: 35557747 PMCID: PMC9090346 DOI: 10.1080/15685551.2022.2072697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The improvement of the crystallization of poly(lactic acid) (PLA) is one of the key areas to allow PLA to perform better at higher temperature and load bearing. Due to its slow crystallization rate, either organic or inorganic nucleating agents (NAs) can be used to improve the crystallization rate of PLA. In the case of organic NAs, aromatic sulfonate salt and bisamide compounds are promising ones because they can control better clarity. The aim of this work was to study the crystallization behavior of PLA using as-synthesized dimethyl 5-sulfoisophthalate sodium salt (SSIPA) as a nucleating agent in comparison with the commercial sulfonate salt (LAK-301). Two grades of PLA (PLA L105 and PLA 3251D) were used in this study. PLA samples were prepared by internal mixer and compression molding. All samples were investigated by DSC and POM. The results from DSC showed that after introducing the nucleating agents into PLA, the crystallinity in all samples was improved. The highest crystallinity at 57.48% was obtained from PLA L105/SSIPA1.0. Isothermal crystallization kinetics showed the improvement in overall crystallization rate of PLA with nucleating agents. The lowest half time crystallization obtained was 1.19 min for PLA L105/SSIPA1.0 at 135 °C. The results from POM indicated the substantial increase of the nucleus density and smaller spherulite size upon adding nucleating agents.
Collapse
Affiliation(s)
- Pasawat Jongpanya-Ngam
- Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom, Thailand
| | - Rattikarn Khankrua
- Department of Materials Engineering, Faculty of Engineering, Rajamangala University of Technology Rattanakosin, Nakhon Pathom, Thailand
| | - Manus Seadan
- Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom, Thailand
| | - Supakij Suttiruengwong
- Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom, Thailand
| |
Collapse
|
4
|
Compatibilization of Poly(Lactic Acid) (PLA)/Plasticized Cellulose Acetate Extruded Blends through the Addition of Reactively Extruded Comb Copolymers. Molecules 2021; 26:molecules26072006. [PMID: 33916068 PMCID: PMC8037935 DOI: 10.3390/molecules26072006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/11/2021] [Accepted: 03/23/2021] [Indexed: 11/17/2022] Open
Abstract
In the perspective of producing a rigid renewable and environmentally friendly rigid packaging material, two comb-like copolymers of cellulose acetate (AC) and oligo(lactic acid) OLA, feeding different percentages of oligo(lactic acid) segments, were prepared by chemical synthesis in solvent or reactive extrusion in the melt, using a diepoxide as the coupling agent and were used as compatibilizers for poly(lactic acid)/plasticized cellulose acetate PLA/pAC blends. The blends were extruded at 230 °C or 197 °C and a similar compatibilizing behavior was observed for the different compatibilizers. The compatibilizer C1 containing 80 wt% of AC and 14 wt% of OLA resulted effective in compatibilization and it was easily obtained by reactive extrusion. Considering these results, different PLAX/pAC(100-X) compounds containing C1 as the compatibilizer were prepared by extrusion at 197 °C and tested in terms of their tensile and impact properties. Reference materials were the uncompatibilized corresponding blend (PLAX/pAC(100-X)) and the blend of PLA, at the same wt%, with C1. Significant increase in Young’s modulus and tensile strength were observed in the compatibilized blends, in dependence of their morphologic features, suggesting the achievement of an improved interfacial adhesion thanks to the occurred compatibilization.
Collapse
|
5
|
Mathe S, Dimonie D, Cristea M. Thermal analysis and polarized light microscopy as methods to study the increasing of the durability of PLA designed for 3D printing. INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION 2021. [DOI: 10.1080/1023666x.2021.1880111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Silvia Mathe
- Doctoral School of Applied Chemistry and Materials Science, Politehnica University of Bucharest, Bucharest, Romania
| | - Doina Dimonie
- National Institute of Research and Development in Chemistry and Petrochemistry, Bucharest, Romania
| | - Mariana Cristea
- Institute of Macromolecular Chemistry “Petru Poni”, Iasi, Romania
| |
Collapse
|
6
|
Barczewski M, Mysiukiewicz O, Lewandowski K, Nowak D, Matykiewicz D, Andrzejewski J, Skórczewska K, Piasecki A. Effect of Basalt Powder Surface Treatments on Mechanical and Processing Properties of Polylactide-Based Composites. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E5436. [PMID: 33260378 PMCID: PMC7730719 DOI: 10.3390/ma13235436] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 12/11/2022]
Abstract
Legislative restrictions and the needs of consumers have created a demand for sustainable materials. Polylactide (PLA) is a biodegradable polyester with advantageous mechanical properties, however, due to its low crystallization rate, it also has low thermomechanical stability. Its range of application temperatures can be widened using nucleating agents and fillers including basalt powder (BP), a waste product from the mining industry. This study analyzed the possibility of enhancing the properties of a PLA-BP composite by chemically treating the filler. Basalt powder was subjected to silanization with 3-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane and mixed with PLA at 5-20 wt%. The nucleating effect of a potassium salt of 3,5-bis(methoxycarbonyl) (LAK-301) in the silanized composite was also evaluated. The properties of the materials with silanized BP were compared with the unmodified basalt powder. The miscibility of the filler and the polymer was assessed by oscillatory rheometry. The structure of the composites was studied using scanning electron microscopy and their thermomechanical properties were analyzed using dynamic mechanical thermal analysis. Mechanical properties such as tensile strength, hardness and impact strength, and heat deflection temperature of the materials were also determined. It was concluded that BP-filled nucleated PLA composites presented satisfactory thermomechanical stability without silanization, but chemical treatment could improve the matrix-filler interactions.
Collapse
Affiliation(s)
- Mateusz Barczewski
- Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland; (O.M.); (D.N.); (D.M.); (J.A.)
| | - Olga Mysiukiewicz
- Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland; (O.M.); (D.N.); (D.M.); (J.A.)
| | - Krzysztof Lewandowski
- Faculty of Chemical Technology and Engineering, UTP University of Science and Technology, Seminaryjna 3, 85-326 Bydgoszcz, Poland; (K.L.); (K.S.)
| | - Daniel Nowak
- Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland; (O.M.); (D.N.); (D.M.); (J.A.)
| | - Danuta Matykiewicz
- Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland; (O.M.); (D.N.); (D.M.); (J.A.)
| | - Jacek Andrzejewski
- Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland; (O.M.); (D.N.); (D.M.); (J.A.)
| | - Katarzyna Skórczewska
- Faculty of Chemical Technology and Engineering, UTP University of Science and Technology, Seminaryjna 3, 85-326 Bydgoszcz, Poland; (K.L.); (K.S.)
| | - Adam Piasecki
- Institute of Materials Engineering, Poznan University of Technology, Jana Pawła II 24, 60-965 Poznan, Poland;
| |
Collapse
|
7
|
Warner M, Engler A, Kohl PA. Improvement in the transience and mechanical performance of flexible Poly(phthalaldehyde) substrates. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
8
|
Moraczewski K, Malinowski R, Sikorska W, Karasiewicz T, Stepczyńska M, Jagodziński B, Rytlewski P. Composting of Polylactide Containing Natural Anti-Aging Compounds of Plant Origin. Polymers (Basel) 2019; 11:polym11101582. [PMID: 31569774 PMCID: PMC6835566 DOI: 10.3390/polym11101582] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/25/2019] [Accepted: 09/25/2019] [Indexed: 12/12/2022] Open
Abstract
The paper presents the effects of biodegradation of polylactide containing natural anti-aging compounds. Polymer containing 0.5; 5 and 10 wt % of coffee, cocoa or cinnamon extracts were subjected to industrial composting for 7, 14, 21 or 28 days. The effect of the composting process on polylactide properties was examined based on visual assessment, scanning electron microscopy, average molecular weight, differential scanning calorimetry, thermogravimetry, and tensile strength. The impact of the tested extracts on the effects of the composting process was compared with the impact of a commercially available anti-aging compound. It was found that the tested extracts in most cases did not adversely affect the effects of the composting process compared to pure polylactide, often resulting in intensification of biodegradation processes. As a result of the composting process, changes in the macro- and microscopic appearance of the samples and a decrease in molecular weight, phase transition temperatures, thermal resistance, and thermal strength were observed on a scale close to or greater than the reference anti-aging compound.
Collapse
Affiliation(s)
- Krzysztof Moraczewski
- Institute of Materials Engineering, Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz, Poland.
| | - Rafał Malinowski
- The Łukasiewicz Research Network-Institute for Engineering of Polymer Materials and Dyes, Marii Skłodowskiej-Curie 55, 87-100 Toruń, Poland.
| | - Wanda Sikorska
- Centre of Polymer and Carbon Materials of the Polish Academy of Sciences, Marii Curie-Skłodowskiej 34, 41-819 Zabrze, Poland.
| | - Tomasz Karasiewicz
- Institute of Materials Engineering, Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz, Poland.
| | - Magdalena Stepczyńska
- Institute of Materials Engineering, Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz, Poland.
| | - Bartłomiej Jagodziński
- Institute of Materials Engineering, Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz, Poland.
| | - Piotr Rytlewski
- Institute of Materials Engineering, Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz, Poland.
| |
Collapse
|
9
|
Shah TV, Vasava DV. A glimpse of biodegradable polymers and their biomedical applications. E-POLYMERS 2019. [DOI: 10.1515/epoly-2019-0041] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AbstractOver the past two decades, biodegradable polymers (BPs) have been widely used in biomedical applications such as drug carrier, gene delivery, tissue engineering, diagnosis, medical devices, and antibacterial/antifouling biomaterials. This can be attributed to numerous factors such as chemical, mechanical and physiochemical properties of BPs, their improved processibility, functionality and sensitivity towards stimuli. The present review intended to highlight main results of research on advances and improvements in terms of synthesis, physical properties, stimuli response, and/or applicability of biodegradable plastics (BPs) during last two decades, and its biomedical applications. Recent literature relevant to this study has been cited and their developing trends and challenges of BPs have also been discussed.
Collapse
Affiliation(s)
- Tejas V. Shah
- Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad, Gujarat- 380009, India
| | - Dilip V. Vasava
- Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad, Gujarat- 380009, India
| |
Collapse
|
10
|
Abstract
Consumer awareness about the damages that plastic packaging waste cause to the environment, coupled with bio-economy and circular economy policies, are pushing plastic packaging versus the use of bio-based and biodegradable materials. In this contest, even cosmetic packaging is looking for sustainable solutions, and research is focusing on modifying bio-based and biodegradable polymers to meet the challenging requirements for cosmetic preservation, while maintaining sustainability and biodegradability. Several bio-based and biodegradable polymers such as poly(lactic acid), polyhydroxyalkanoates, polysaccharides, etc., are available, and some first solutions for both rigid and flexible packaging are already present on the market, while many others are under study and optimization. A fruitful cooperation among researchers and industries will drive the cosmetic sector toward being more ecological and contributing to save our environment.
Collapse
|
11
|
Coltelli MB, Cinelli P, Gigante V, Aliotta L, Morganti P, Panariello L, Lazzeri A. Chitin Nanofibrils in Poly(Lactic Acid) (PLA) Nanocomposites: Dispersion and Thermo-Mechanical Properties. Int J Mol Sci 2019; 20:E504. [PMID: 30682847 PMCID: PMC6386964 DOI: 10.3390/ijms20030504] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/17/2019] [Accepted: 01/18/2019] [Indexed: 11/16/2022] Open
Abstract
Chitin-nanofibrils are obtained in water suspension at low concentration, as nanoparticles normally are, to avoid their aggregation. The addition of the fibrils in molten PLA during extrusion is thus difficult and disadvantageous. In the present paper, the use of poly(ethylene glycol) (PEG) is proposed to prepare a solid pre-composite by water evaporation. The pre-composite is then added to PLA in the extruder to obtain transparent nanocomposites. The amount of PEG and chitin nanofibrils was varied in the nanocomposites to compare the reinforcement due to nanofibrils and plasticization due to the presence of PEG, as well as for extrapolating, where possible, the properties of reinforcement due to chitin nanofibrils exclusively. Thermal and morphological properties of nanocomposites were also investigated. This study concluded that chitin nanofibrils, added as reinforcing filler up to 12% by weight, do not properties alter the properties of the PLA based material; hence, this additive can be used in bioplastic items mainly exploiting their intrinsic anti-microbial and skin regenerating properties.
Collapse
Affiliation(s)
- Maria-Beatrice Coltelli
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National InterUniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
| | - Patrizia Cinelli
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National InterUniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
| | - Vito Gigante
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National InterUniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
| | - Laura Aliotta
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National InterUniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
| | - Pierfrancesco Morganti
- Skin Pharmacology and Dermatology Unit, Campania University "Luigi Vanvitelli", 80100 Naples, Italy.
- MAVI SUD, Aprilia (LT), 04011 Aprilia, Italy.
| | - Luca Panariello
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National InterUniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
| | - Andrea Lazzeri
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National InterUniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
| |
Collapse
|
12
|
Barbi S, Messori M, Manfredini T, Pini M, Montorsi M. Rational design and characterization of bioplastics from
Hermetia illucens
prepupae proteins. Biopolymers 2018; 110:e23250. [DOI: 10.1002/bip.23250] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/03/2018] [Accepted: 12/07/2018] [Indexed: 01/03/2023]
Affiliation(s)
- Silvia Barbi
- Interdepartmental Center for Applied Research and Services in Advanced Mechanics and MotoringUniversity of Modena and Reggio Emilia Modena Italy
| | - Massimo Messori
- Department of Engineering “E. Ferrari”University of Modena and Reggio Emilia Modena Italy
| | - Tiziano Manfredini
- Department of Engineering “E. Ferrari”University of Modena and Reggio Emilia Modena Italy
| | - Martina Pini
- Department of Science and Methods for EngineeringUniversity of Modena and Reggio Emilia Reggio Emilia Italy
| | - Monia Montorsi
- Department of Science and Methods for EngineeringUniversity of Modena and Reggio Emilia Reggio Emilia Italy
| |
Collapse
|
13
|
Geng Z, Bian S, Zhen W, Song Z, Wang X. Preparation, structure-property relationships of zinc oxide pillared organic layered double hydroxides and its effect on the performance of poly (lactic acid). POLYM-PLAST TECH MAT 2018. [DOI: 10.1080/03602559.2018.1520246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Zhongxing Geng
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Region, Xinjiang University, Urumqi, China
| | - Shenzhen Bian
- Xinjiang Institute of Light Industry Technology, Urumqi, China
| | - Weijun Zhen
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Region, Xinjiang University, Urumqi, China
| | - Zhongbo Song
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Region, Xinjiang University, Urumqi, China
| | - Xuefeng Wang
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Region, Xinjiang University, Urumqi, China
| |
Collapse
|
14
|
Preparation of Water Suspensions of Nanocalcite for Cultural Heritage Applications. NANOMATERIALS 2018; 8:nano8040254. [PMID: 29671800 PMCID: PMC5923584 DOI: 10.3390/nano8040254] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/10/2018] [Accepted: 04/16/2018] [Indexed: 11/17/2022]
Abstract
The consolidation of degraded carbonate stone used in ancient monuments is an important topic for European cultural heritage conservation. The products most frequently used as consolidants are based on tetraalkoxy- or alkylalkoxy-silanes (in particular tetraethyl-orthosilicate, TEOS), resulting in the formation of relatively stable amorphous silica or alkylated (hydrophobic) silica inside the stone pores. However, silica is not chemically compatible with carbonate stones; in this respect, nanocalcite may be a suitable alternative. The present work concerns the preparation of water suspensions of calcite nanoparticles (CCNPs) by controlled carbonation of slaked lime using a pilot-scale reactor. A simplified design of experiment was adopted for product optimization. Calcite nanoparticles of narrow size distribution averaging about 30 nm were successfully obtained, the concentration of the interfacial agent and the size of CaO being the most critical parameters. Primary nanoparticle aggregation causing flocculation could be substantially prevented by the addition of polymeric dispersants. Copolymer-based dispersants were produced in situ by controlled heterophase polymerisation mediated by an amphiphilic macro-RAFT (reversible addition-fragmentation transfer) agent. The stabilized CCNP aqueous dispersions were then applied on carbonate and silicate substrates; Scanning Electron Microscopy (SEM)analysis of cross-sections allowed the evaluation of pore penetration, interfacial binding, and bridging (gap-filling) properties of these novel consolidants.
Collapse
|
15
|
Geng Z, Zhen W, Song Z, Wang X. Synthesis, characterization of layered double hydroxide-poly(methylmethacrylate) graft copolymers via activators regenerated by electron transfer for atom transfer radical polymerization and its effect on the performance of poly(lactic acid). POLYM ADVAN TECHNOL 2018. [DOI: 10.1002/pat.4283] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Zhongxing Geng
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Autonomous Region; Xinjiang University; Urumqi 830046 China
| | - Weijun Zhen
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Autonomous Region; Xinjiang University; Urumqi 830046 China
| | - Zhongbo Song
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Autonomous Region; Xinjiang University; Urumqi 830046 China
| | - Xuefeng Wang
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education and Xinjiang Uygur Autonomous Region; Xinjiang University; Urumqi 830046 China
| |
Collapse
|
16
|
Di Lorenzo ML, Androsch R. Accelerated crystallization of high molar mass poly( l / d -lactic acid) by blending with low molar mass poly( l -lactic acid). Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.01.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
17
|
Mallegni N, Phuong TV, Coltelli MB, Cinelli P, Lazzeri A. Poly(lactic acid) (PLA) Based Tear Resistant and Biodegradable Flexible Films by Blown Film Extrusion. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E148. [PMID: 29342099 PMCID: PMC5793646 DOI: 10.3390/ma11010148] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/25/2017] [Accepted: 01/09/2018] [Indexed: 11/16/2022]
Abstract
Poly(lactic acid) (PLA) was melt mixed in a laboratory extruder with poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) in the presence of polypropylene glycol di glycidyl ether (EJ400) that acted as both plasticizer and compatibilizer. The process was then scaled up in a semi-industrial extruder preparing pellets having different content of a nucleating agent (LAK). All of the formulations could be processed by blowing extrusion and the obtained films showed mechanical properties dependent on the LAK content. In particular the tearing strength showed a maximum like trend in the investigated composition range. The films prepared with both kinds of blends showed a tensile strength in the range 12-24 MPa, an elongation at break in the range 150-260% and a significant crystallinity.
Collapse
Affiliation(s)
- Norma Mallegni
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
| | - Thanh Vu Phuong
- Department of Chemical Engineering, Can Tho University, 3/2 Street, Can Tho 90000, Vietnam.
| | - Maria-Beatrice Coltelli
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
| | - Patrizia Cinelli
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
- National Research Council, Institute of Chemical Physical Processes, Via Moruzzi 1, 56124 Pisa, Italy.
| | - Andrea Lazzeri
- Department of Civil and Industrial Engineering, University of Pisa, Via Diotisalvi 2, 56122 Pisa, Italy.
| |
Collapse
|
18
|
|