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de Morais LA, de Souza Neto FN, Hosida TY, dos Santos DM, de Almeida BC, Frollini E, Filho SPC, Barbosa DDB, de Camargo ER, Delbem ACB. Synthesis, Characterization, and Evaluation of the Antimicrobial Effects and Cytotoxicity of a Novel Nanocomposite Based on Polyamide 6 and Trimetaphosphate Nanoparticles Decorated with Silver Nanoparticles. Antibiotics (Basel) 2024; 13:340. [PMID: 38667015 PMCID: PMC11047323 DOI: 10.3390/antibiotics13040340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 04/29/2024] Open
Abstract
This study aimed to develop a polymeric matrix of polyamide-6 (P6) impregnated with trimetaphosphate (TMP) nanoparticles and silver nanoparticles (AgNPs), and to evaluate its antimicrobial activity, surface free energy, TMP and Ag+ release, and cytotoxicity for use as a support in dental tissue. The data were subjected to statistical analysis (p < 0.05). P6 can be incorporated into TMP without altering its properties. In the first three hours, Ag+ was released for all groups decorated with AgNPs, and for TMP, the release only occurred for the P6-TMP-5% and P6-TMP-10% groups. In the inhibition zones, the AgNPs showed activity against both microorganisms. The P6-TMP-2.5%-Ag and P6-TMP-5%-Ag groups with AgNPs showed a greater reduction in CFU for S. mutans. For C. albicans, all groups showed a reduction in CFU. The P6-TMP groups showed higher cell viability, regardless of time (p < 0.05). The developed P6 polymeric matrix impregnated with TMP and AgNPs demonstrated promising antimicrobial properties against the tested microorganisms, making it a potential material for applications in scaffolds in dental tissues.
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Affiliation(s)
- Leonardo Antônio de Morais
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, Araçatuba 16015-050, São Paulo, Brazil; (L.A.d.M.); (F.N.d.S.N.); (T.Y.H.); (B.C.d.A.); (D.d.B.B.)
| | - Francisco Nunes de Souza Neto
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, Araçatuba 16015-050, São Paulo, Brazil; (L.A.d.M.); (F.N.d.S.N.); (T.Y.H.); (B.C.d.A.); (D.d.B.B.)
| | - Thayse Yumi Hosida
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, Araçatuba 16015-050, São Paulo, Brazil; (L.A.d.M.); (F.N.d.S.N.); (T.Y.H.); (B.C.d.A.); (D.d.B.B.)
| | - Danilo Martins dos Santos
- Sao Carlos Institute of Chemistry, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, São Carlos 13566-590, São Paulo, Brazil; (D.M.d.S.); (E.F.); (S.P.C.F.)
| | - Bianca Carvalho de Almeida
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, Araçatuba 16015-050, São Paulo, Brazil; (L.A.d.M.); (F.N.d.S.N.); (T.Y.H.); (B.C.d.A.); (D.d.B.B.)
| | - Elisabete Frollini
- Sao Carlos Institute of Chemistry, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, São Carlos 13566-590, São Paulo, Brazil; (D.M.d.S.); (E.F.); (S.P.C.F.)
| | - Sergio Paulo Campana Filho
- Sao Carlos Institute of Chemistry, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, São Carlos 13566-590, São Paulo, Brazil; (D.M.d.S.); (E.F.); (S.P.C.F.)
| | - Debora de Barros Barbosa
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, Araçatuba 16015-050, São Paulo, Brazil; (L.A.d.M.); (F.N.d.S.N.); (T.Y.H.); (B.C.d.A.); (D.d.B.B.)
| | - Emerson Rodrigues de Camargo
- Center for Exact Sciences and Technology, Federal University of São Carlos (UFSCAR), Av. Trab. São Carlense, 400, São Carlos 13566-590, São Paulo, Brazil;
| | - Alberto Carlos Botazzo Delbem
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, Araçatuba 16015-050, São Paulo, Brazil; (L.A.d.M.); (F.N.d.S.N.); (T.Y.H.); (B.C.d.A.); (D.d.B.B.)
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2
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Furlan Sandrini DM, Morgado DL, de Oliveira AJA, de Moraes DA, Varanda LC, Frollini E. Cellulose esters: Synthesis for further formation of films with magnetite nanoparticles incorporated. Int J Biol Macromol 2024; 264:130594. [PMID: 38437931 DOI: 10.1016/j.ijbiomac.2024.130594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 02/07/2024] [Accepted: 03/01/2024] [Indexed: 03/06/2024]
Abstract
This study investigated the homogeneous synthesis of cellulose acetate (CA) and propionate (CP) with varying degrees of substitution (DS) from sisal cellulose in a N, N-dimethylacetamide/lithium chloride (DMAc/LiCl) solvent system. These esters were used to prepare neat (CADSF/CPDSF) and nanocomposite films (CADSFFe/CPDSFFe) from prior synthesized magnetite nanoparticles (NPs, Fe3O4, 5.1 ± 0.5 nm). Among the CA and CP series, the composite CA0.7FFe and the neat CP0.7F films exhibited the highest modulus of elasticity, 2105 MPa and 2768 MPa, respectively, probably a consequence of the continuous fibrous structures present on the surface of these films. Microsphere formation on the film's surface was observed in scanning electron microscopy micrographs. This points to applications in the controlled release of targeted substances. The VSM analysis showed that the cellulosic matrices preserved the superparamagnetic characteristics of the NPs. This study suggested a reduced coupling effect between nanoparticles inside polymeric films due to magnetic saturation at low fields. CA0.7FFe and CA1.3FFe composite films reached a saturation magnetization (MSAT) of 46 emu/g around 7 kOe field. Hosting magnetite nanoparticles in cellulose ester matrices may be an interesting way to develop new functional cellulose-based materials, which have the potential for diverse applications, including microelectromechanical systems and microsensors.
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Affiliation(s)
- Daiana M Furlan Sandrini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Daniella Lury Morgado
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, São Carlos, São Paulo, Brazil
| | | | - Daniel A de Moraes
- Colloidal Materials Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Laudemir C Varanda
- Colloidal Materials Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, São Carlos, São Paulo, Brazil.
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3
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Rodrigues BVM, Polez RT, El Seoud OA, Frollini E. Cellulose acylation in homogeneous and heterogeneous media: Optimization of reactions conditions. Int J Biol Macromol 2023; 243:125256. [PMID: 37295694 DOI: 10.1016/j.ijbiomac.2023.125256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/28/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023]
Abstract
The dependence of the DS on the acid anhydride/anhydroglucose unit ((RCO)2O/AGU) molar ratio was correlated using second-order polynomials. The regression coefficients of the (RCO)2O/AGU terms showed that increasing the length of the RCO group of the anhydride led to lower values of DS. For acylation under heterogeneous reaction conditions, the following were employed: acid anhydrides and butyryl chloride as acylating agents; iodine as a catalyst; N,N-dimethylformamide (DMF) as a solvent, pyridine, and triethylamine as solvents and catalysts. For acylation using acetic anhydride plus iodine, the values of DS correlate with reaction time by a second-order polynomial. Due to its role as a polar solvent and a nucleophilic catalyst, pyridine was the most effective base catalyst, independent of the acylating agent (butyric anhydride and butyryl chloride).
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Affiliation(s)
- Bruno Vinicius Manzolli Rodrigues
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Carlos, SP, Brazil
| | - Roberta Teixeira Polez
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Carlos, SP, Brazil
| | - Omar A El Seoud
- Polymer and Surfactant Group, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, SP, Brazil
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Carlos, SP, Brazil.
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Porto DS, de Faria CMG, Inada NM, Frollini E. Polyurethane films formation from microcrystalline cellulose as a polyol and cellulose nanocrystals as additive: Reactions favored by the low viscosity of the source of isocyanate groups used. Int J Biol Macromol 2023; 236:124035. [PMID: 36921831 DOI: 10.1016/j.ijbiomac.2023.124035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/17/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023]
Abstract
To simultaneously form films while synthesizing solvent-free and catalyst-free bio-based polyurethanes, hexamethylene diisocyanate trimer was selected as an isocyanate group source to produce a low-viscosity reaction medium for dispersing high contents of microcrystalline cellulose (MCC, polyol) and cellulose nanocrystals (CNC). Castor oil was used as an additional polyol source. Up to 80 % of the MCC was dispersed, producing a film exhibiting the highest Tg (72 °C), tensile strength (18 MPa), and Young's modulus (522.4 MPa). 12.5 % (30 % MCC) and 7.5 % (50 % MCC) of CNC dispersed in the reaction medium formed films stiffer than their counterparts. All the films exhibited transparency and high crystallinity. The contact angle/zeta potential (ζ) indicated hydrophobic film surfaces. At pH 7.4, ζ suggested that the films interacted with physiological fluids favorably. The films were non-cytotoxic, and the composites exhibited cell growth compared with the control. The reported results, as far as it is known, are unprecedented.
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Affiliation(s)
- Deyvid S Porto
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil
| | - Clara Maria Gonçalves de Faria
- São Carlos Institute of Physics, University of São Paulo, Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil
| | - Natalia M Inada
- São Carlos Institute of Physics, University of São Paulo, Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil.
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5
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Passos de Oliveira Santos R, Hao J, Daniel de Mello Innocentini M, Frollini E, Savastano Junior H, Rutledge GC. Composite electrospun membranes based on polyacrylonitrile and cellulose nanofibrils: relevant properties for their use as active filter layers. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Parrone D, Frollini E, Masciale R, Melita M, Passarella G, Preziosi E, Ghergo S. A double pre-selection method for natural background levels assessment in coastal groundwater bodies. Environ Pollut 2022; 313:120076. [PMID: 36058317 DOI: 10.1016/j.envpol.2022.120076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/03/2022] [Accepted: 08/27/2022] [Indexed: 06/15/2023]
Abstract
To evaluate the chemical status of groundwater bodies (GWB) according to the European Groundwater Directive, EU Member States are required to take into account natural background levels (NBLs) where needed. Assessing the NBLs in coastal GWBs is complicated by seawater intrusion which can be amplified by groundwater withdrawals increasing the salinization of such groundwater systems. This paper proposes a new method for the NBLs assessment in coastal areas based on a double pre-selection (PS) with fixed/dynamic limits. A case study in the Apulia region, located in southeastern Italy, is proposed, where we investigated four adjacent GWBs which form the complex karst, fractured Murgia aquifer, hosted in the Jurassic-Cretaceous carbonate platform, bounded by two seas and sustained by saltwater of marine intrusion in the coastal areas. Data related to 139 monitoring stations (MSs) of the regional groundwater monitoring network were used. The first PS, "static", based on a fixed limit of anthropogenic contamination markers (NO3 and NH4), allows for the elimination of MSs impacted by human activities. On these, the second PS, "dynamic", based on the identification of Cl anomalous values, allows for the identification of additional MSs affected by saline contamination. The residual dataset of MSs was used for the definition of NBLs of Cl, SO4, F and B. A statistical comparison with historical Cl observations finally allowed us to verify if the salinity of current groundwater is representative of pristine conditions. The calculated NBLs of salinity parameters are higher for the two coastal GWBs, with chloride values between 0.8 and 2 mg/L. Conversely, fluorides always show very low NBLs. The double PS approach seems more effective for NBLs calculation in coastal aquifers affected by saline contamination, where the use of a fixed Cl limit fails. It may respond to the international needs for a standardized procedure for NBL assessment.
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Affiliation(s)
- D Parrone
- IRSA-CNR, Water Research Institute - National Research Council, Via Salaria Km 29.300, PB 10, 00015 Monterotondo, Rome, Italy
| | - E Frollini
- IRSA-CNR, Water Research Institute - National Research Council, Via Salaria Km 29.300, PB 10, 00015 Monterotondo, Rome, Italy.
| | - R Masciale
- IRSA-CNR, Water Research Institute - National Research Council, V.le Francesco de Blasio 5, 70132, Bari, Italy
| | - M Melita
- IRSA-CNR, Water Research Institute - National Research Council, Via Salaria Km 29.300, PB 10, 00015 Monterotondo, Rome, Italy
| | - G Passarella
- IRSA-CNR, Water Research Institute - National Research Council, V.le Francesco de Blasio 5, 70132, Bari, Italy
| | - E Preziosi
- IRSA-CNR, Water Research Institute - National Research Council, Via Salaria Km 29.300, PB 10, 00015 Monterotondo, Rome, Italy
| | - S Ghergo
- IRSA-CNR, Water Research Institute - National Research Council, Via Salaria Km 29.300, PB 10, 00015 Monterotondo, Rome, Italy
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7
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Polez RT, Rodrigues BVM, El Seoud OA, Frollini E. Electrospinning of cellulose carboxylic esters synthesized under homogeneous conditions: Effects of the ester degree of substitution and acyl group chain length on the morphology of the fabricated mats. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Rana AK, Frollini E, Thakur VK. Cellulose nanocrystals: Pretreatments, preparation strategies, and surface functionalization. Int J Biol Macromol 2021; 182:1554-1581. [PMID: 34029581 DOI: 10.1016/j.ijbiomac.2021.05.119] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/08/2021] [Accepted: 05/16/2021] [Indexed: 01/04/2023]
Abstract
Cellulose nanocrystals (CNCs) have attracted great interest from researchers from academic and industrial areas because of their interesting structural features and unique physicochemical properties, such as magnificent mechanical strength, high surface area, and many hydroxyl groups for chemical modification, low density, and biodegradability. CNCs are an outstanding contender for applications in assorted fields comprehensive of, e.g., biomedical, electronic gadgets, water purifications, nanocomposites, membranes. Additionally, a persistent progression is going on in the extraction and surface modification of cellulose nanocrystals to fulfill the expanding need of producers to fabricate cellulose nanocrystals-based materials. In this review, the foundation of nanocellulose that emerged from lignocellulosic biomass and recent development in extraction/preparation of cellulose nanocrystals and different types of cellulose nanocrystal surface modification techniques are summed up. The different sorts of cellulose modification reactions that have been discussed are acetylation, oxidations, esterifications, etherifications, ion-pair formation, hydrogen bonding, silanization, nucleophilic substitution reactions, and so forth. The mechanisms of surface functionalization reactions are also introduced and considered concerning the impact on the reactions. Moreover, the primary association of cellulose and different forms of nanocellulose has likewise been examined for beginners in this field.
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Affiliation(s)
| | - Elisabete Frollini
- São Carlos Institute of Chemistry, Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, University of São Paulo, C.P. 780, São Carlos, SP CEP 13560-970, Brazil.
| | - Vijay Kumar Thakur
- Biorefining and Advanced Materials Research Center, Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, UK; Department of Mechanical Engineering, School of Engineering, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India.
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Kaschuk J, Borghei M, Solin K, Tripathi A, Khakalo A, Leite FA, Branco A, Amores de Sousa MC, Frollini E, Rojas OJ. Cross-Linked and Surface-Modified Cellulose Acetate as a Cover Layer for Paper-Based Electrochromic Devices. ACS Appl Polym Mater 2021; 3:2393-2401. [PMID: 34308357 PMCID: PMC8290922 DOI: 10.1021/acsapm.0c01252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 12/30/2020] [Indexed: 05/26/2023]
Abstract
We studied the surface and microstructure of cellulose acetate (CA) films to tailor their barrier and mechanical properties for application in electrochromic devices (ECDs). Cross-linking of CA was carried out with pyromellitic dianhydride to enhance the properties relative to unmodified CA: solvent resistance (by 43% in acetone and 37% in DMSO), strength (by 91% for tensile at break), and barrier (by 65% to oxygen and 92% to water vapor). Surface modification via tetraethyl orthosilicate and octyltrichlorosilane endowed the films with hydrophobicity, stiffness, and further enhanced solvent resistance. A detailed comparison of structural, chemical, surface, and thermal properties was performed by using X-ray diffraction, dynamic mechanical analyses, Fourier-transform infrared spectroscopy, and atomic force microscopy. Coplanar ECDs were synthesized by incorporating a hydrogel electrolyte comprising TEMPO-oxidized cellulose nanofibrils and an ionic liquid. When applied as the top layer in the ECDs, cross-linked and hydrophobized CA films extended the functionality of the assembled displays. The results indicate excellent prospects for CA films in achieving environmental-friendly ECDs that can replace poly(ethylene terephthalate)-based counterparts.
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Affiliation(s)
- Joice
Jaqueline Kaschuk
- Macromolecular
Materials and Lignocellulosic Fibers Group, Center for Research on
Science and Technology of BioResources, Institute of Chemistry of
São Carlos, University of São
Paulo, CP 780, 13560-970 São Carlos, São Paulo, Brazil
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Vuorimiehentie 1, FI-00076 Espoo, Finland
| | - Maryam Borghei
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Vuorimiehentie 1, FI-00076 Espoo, Finland
| | - Katariina Solin
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Vuorimiehentie 1, FI-00076 Espoo, Finland
| | - Anurodh Tripathi
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Vuorimiehentie 1, FI-00076 Espoo, Finland
- Department
of Chemical and Biomolecular Engineering, North Carolina State University, 27695 Raleigh, North Carolina, United States
| | - Alexey Khakalo
- VTT
Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044, VTT Espoo, Finland
| | | | - Aida Branco
- Ynvisible
SA, Rua Quinta do Bom
Retiro 12C, 2820-690 Charneca da Caparica, Portugal
| | | | - Elisabete Frollini
- Macromolecular
Materials and Lignocellulosic Fibers Group, Center for Research on
Science and Technology of BioResources, Institute of Chemistry of
São Carlos, University of São
Paulo, CP 780, 13560-970 São Carlos, São Paulo, Brazil
| | - Orlando J. Rojas
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Vuorimiehentie 1, FI-00076 Espoo, Finland
- Bioproducts
Institute, Department of Chemical and Biological Engineering, Department
of Chemistry and Department of Wood Science, The University of British Columbia, 2360 East Mall, BC
V6T 1Z3 Vancouver, Canada
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Queiroz BG, Ciol H, Inada NM, Frollini E. Hydrogel from all in all lignocellulosic sisal fibers macromolecular components. Int J Biol Macromol 2021; 181:978-989. [PMID: 33892029 DOI: 10.1016/j.ijbiomac.2021.04.088] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 01/12/2023]
Abstract
The heterogeneous structure of lignocellulosic biomass makes it difficult to dissolve its main components (cellulose, hemicelluloses, and lignin) by solvent action with the aim of further applying the mixture of the biological macromolecules generated in the solvent medium. In the present study, the dissolution efficiency (DE) of lignocellulosic sisal fibers in the lithium chloride/dimethylacetamide solvent system (LiCl/DMAc) was evaluated for further application in the formation of hydrogels. Catalytic amounts of trifluoroacetic acid (TFA) were used in some experiments, which increased the DE from 40% to 90%. The regeneration of the solutions, either previously filtered or not, led to hydrogels based on sisal lignocellulosic biomass. In brief, the properties of the hydrogels were influenced by the content of the lignocellulosic components in the hydrogels, present both in the dissolved fraction and in the incorporated undissolved fraction (when nonfiltered solutions were used). Hydrogels presented water absorption up to 7479% and resorption content in the lyophilized hydrogel up to 2133%. Extracts obtained from preselected hydrogels exhibited cell viability up to 127% compared to the control group when in contact with fibroblast cultures, exhibiting their noncytotoxic properties. This attribute increased the range of possible applications of these hydrogels, ranging from agriculture to biocompatible materials.
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Affiliation(s)
- Bianca G Queiroz
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil
| | - Heloísa Ciol
- São Carlos Institute of Physics, University of São Paulo, , Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil
| | - Natalia M Inada
- São Carlos Institute of Physics, University of São Paulo, , Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, São Carlos Institute of Chemistry, Trabalhador São Carlense Ave, 400, 13566-590 São Carlos, SP, Brazil.
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de Oliveira Santos RP, Ramos LA, Frollini E. Bio-based electrospun mats composed of aligned and nonaligned fibers from cellulose nanocrystals, castor oil, and recycled PET. Int J Biol Macromol 2020; 163:878-887. [DOI: 10.1016/j.ijbiomac.2020.07.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/21/2020] [Accepted: 07/07/2020] [Indexed: 11/30/2022]
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12
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Cassales A, Ramos LA, Frollini E. Synthesis of bio-based polyurethanes from Kraft lignin and castor oil with simultaneous film formation. Int J Biol Macromol 2020; 145:28-41. [DOI: 10.1016/j.ijbiomac.2019.12.173] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/19/2019] [Accepted: 12/19/2019] [Indexed: 02/07/2023]
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Kaschuk JJ, Lacerda TM, Frollini E. Investigating effects of high cellulase concentration on the enzymatic hydrolysis of the sisal cellulosic pulp. Int J Biol Macromol 2019; 138:919-926. [DOI: 10.1016/j.ijbiomac.2019.07.173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/28/2019] [Accepted: 07/25/2019] [Indexed: 12/14/2022]
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Passos de Oliveira Santos R, Fernanda Rossi P, Ramos LA, Frollini E. Renewable Resources and a Recycled Polymer as Raw Materials: Mats from Electrospinning of Lignocellulosic Biomass and PET Solutions. Polymers (Basel) 2018; 10:E538. [PMID: 30966572 PMCID: PMC6415374 DOI: 10.3390/polym10050538] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/10/2018] [Accepted: 05/14/2018] [Indexed: 11/17/2022] Open
Abstract
Interest in the use of renewable raw materials in the preparation of materials has been growing uninterruptedly in recent decades. The aim of this strategy is to offer alternatives to the use of fossil fuel-based raw materials and to meet the demand for materials that are less detrimental to the environment after disposal. In this context, several studies have been carried out on the use of lignocellulosic biomass and its main components (cellulose, hemicelluloses, and lignin) as raw materials for polymeric materials. Lignocellulosic fibers have a high content of cellulose, but there has been a notable lack of investigations on application of the electrospinning technique for solutions prepared from raw lignocellulosic biomass, even though the presence of cellulose favors the alignment of the fiber chains during electrospinning. In this investigation, ultrathin (submicrometric) and nanoscale aligned fibers were successfully prepared via electrospinning (room temperature) of solutions prepared with different contents of lignocellulosic sisal fibers combined with recycled poly(ethylene terephthalate) (PET) using trifluoroacetic acid (TFA) as solvent. The "macro" fibers were deconstructed by the action of TFA, resulting in solutions containing their constituents, i.e., cellulose, hemicelluloses, and lignin, in addition to PET. The "macro" sisal fibers were reconstructed at the nanometer and submicrometric scale from these solutions. The SEM micrographs of the mats containing the components of sisal showed distinct fiber networks, likely due to differences in the solubility of these components in TFA and in their dielectric constants. The mechanical properties of the mats (dynamic mechanical analysis, DMA, and tensile properties) were evaluated with the samples positioned both in the direction (dir) of and in opposition (op) to the alignment of the nano and ultrathin fibers, which can be considered a novelty in the analysis of this type of material. DMA showed superior values of storage modulus (E' at 30 °C) for the mats characterized in the preferential direction of fiber alignment. For example, for mats obtained from solutions prepared from a 0.4 ratio of sisal fibers/PET, Sisal/PET0.40dir presented a high E' value of 765 MPa compared to Sisal/PET0.40op that presented an E' value of 88.4 MPa. The fiber alignment did not influence the Tg values (from tan δ peak) of electrospun mats with the same compositions, as they presented similar values for this property. The tensile properties of the electrospun mats were significantly impacted by the alignment of the fibers: e.g., Sisal/PET0.40dir presented a high tensile strength value of 15.72 MPa, and Sisal/PET0.40op presented a value of approximately 2.5 MPa. An opposite trend was observed regarding the values of elongation at break for these materials. Other properties of the mats are also discussed; such as the index of fiber alignment, average porosity, and surface contact angle. To our knowledge, this is the first time that the influence of fiber alignment on the properties of electrospun mats based on untreated lignocellulosic biomass combined with a recycled polymer, such as PET, has been evaluated. The mats obtained in this study have potential for diversified applications, such as reinforcement for polymeric matrices in nanocomposites, membranes for filtration, and support for enzymes, wherein the fiber alignment, together with other evaluated properties, can impact their effectiveness in these applications.
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Affiliation(s)
- Rachel Passos de Oliveira Santos
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, SP, Brazil.
| | - Patrícia Fernanda Rossi
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, SP, Brazil.
| | - Luiz Antônio Ramos
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, SP, Brazil.
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center of Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, SP, Brazil.
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Megiatto JD, Cerrutti BM, Frollini E. Sodium lignosulfonate as a renewable stabilizing agent for aqueous alumina suspensions. Int J Biol Macromol 2016; 82:927-32. [DOI: 10.1016/j.ijbiomac.2015.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/14/2015] [Accepted: 11/01/2015] [Indexed: 10/22/2022]
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Frollini E. Editoral. Polímeros 2015. [DOI: 10.1590/0104-1428.2504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Frollini E. Editorial. Polímeros 2015. [DOI: 10.1590/0104-1428.2503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Oliveira de Castro D, Frollini E, Ruvolo-Filho A, Dufresne A. “Green polyethylene” and curauá cellulose nanocrystal based nanocomposites: Effect of vegetable oils as coupling agent and processing technique. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/polb.23729] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Daniele Oliveira de Castro
- Macromolecular Materials and Lignocellulosic Fibers Group; Institute of Chemistry of São Carlos, University of São Paulo; CP 780 13560-970 São Carlos São Paulo Brazil
- Université Grenoble Alpes; LGP2 F-38000 Grenoble France
- CNRS; LGP2 F-38000 Grenoble France
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group; Institute of Chemistry of São Carlos, University of São Paulo; CP 780 13560-970 São Carlos São Paulo Brazil
| | - Adhemar Ruvolo-Filho
- Department of Materials Engineering; Federal University of São Carlos; CP 676 13565-905 São Carlos São Paulo Brazil
| | - Alain Dufresne
- Université Grenoble Alpes; LGP2 F-38000 Grenoble France
- CNRS; LGP2 F-38000 Grenoble France
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Rodrigues BVM, Ramires EC, Santos RPO, Frollini E. Ultrathin and nanofibers via room temperature electrospinning from trifluoroacetic acid solutions of untreated lignocellulosic sisal fiber or sisal pulp. J Appl Polym Sci 2015. [DOI: 10.1002/app.41826] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Bruno V. M. Rodrigues
- Macromolecular Materials and Lignocellulosic Fibers Group; Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo; 13560-970 São Carlos São Paulo Brazil
| | - Elaine C. Ramires
- Macromolecular Materials and Lignocellulosic Fibers Group; Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo; 13560-970 São Carlos São Paulo Brazil
| | - Rachel P. O. Santos
- Macromolecular Materials and Lignocellulosic Fibers Group; Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo; 13560-970 São Carlos São Paulo Brazil
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group; Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo; 13560-970 São Carlos São Paulo Brazil
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Frollini E. Sobre o ano de 2014. Polímeros 2014. [DOI: 10.1590/0104-1428.ed06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Razera IAT, Silva CGD, Almeida ÉVRD, Frollini E. Treatments of jute fibers aiming at improvement of fiber-phenolic matrix adhesion. Polímeros 2014. [DOI: 10.1590/0104-1428.1738] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Frollini E, Ambrósio JD, Ruvolo Filho AC. Fator de impacto 2013. Polímeros 2014. [DOI: 10.1590/0104-1428.ed04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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de Oliveira Santos RP, Castro DO, Ruvolo-Filho AC, Frollini E. Processing and thermal properties of composites based on recycled PET, sisal fibers, and renewable plasticizers. J Appl Polym Sci 2014. [DOI: 10.1002/app.40386] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Rachel Passos de Oliveira Santos
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources; Institute of Chemistry of São Carlos; University of São Paulo; São Carlos São Paulo Brazil
| | - Daniele Oliveira Castro
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources; Institute of Chemistry of São Carlos; University of São Paulo; São Carlos São Paulo Brazil
| | | | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources; Institute of Chemistry of São Carlos; University of São Paulo; São Carlos São Paulo Brazil
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Morgado DL, Rodrigues BVM, Almeida EVR, Seoud OAE, Frollini E. Bio-based Films from Linter Cellulose and Its Acetates: Formation and Properties. Materials (Basel) 2013; 6:2410-2435. [PMID: 28809281 PMCID: PMC5458961 DOI: 10.3390/ma6062410] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 05/29/2013] [Accepted: 06/03/2013] [Indexed: 11/22/2022]
Abstract
This paper describes the results obtained on the preparation of films composed of linter cellulose and the corresponding acetates. The acetylation was carried out in the LiCl/DMAc solvent system. Films were prepared from a LiCl/DMAc solution of cellulose acetates (degree of substitution, DS 0.8–2.9) mixed with linter cellulose (5, 10 and 15 wt %). Detailed characterization of the films revealed the following: (i) they exhibited fibrous structures on their surfaces. The strong tendency of the linter cellulose chains to aggregate in LiCl/DMAc suggests that these fibrous elements consist of cellulose chains, as can be deduced from SEM images of the film of cellulose proper; (ii) the cellulose acetate films obtained from samples with DS 2.1 and 2.9 exhibited microspheres on the surface, whose formation seems to be favored for acetates with higher DS; (iii) AFM analysis showed that, in general, the presence of cellulose increased both the asperity thickness and the surface roughness of the analyzed films, indicating that cellulose chains are at least partially organized in domains and not molecularly dispersed between acetate chains; and (iv) the films prepared from cellulose and acetates exhibited lower hygroscopicity than the acetate films, also suggesting that the cellulose chains are organized into domains, probably due to strong intermolecular interactions. The linter and sisal acetates (the latter from a prior study), and their respective films, were prepared using the same processes; however, the two sets of films presented more differences (as in humidity absorption, optical, and tensile properties) than similarities (as in some morphological aspects), most likely due to the different properties of the starting materials. Potential applications of the films prepared in tissue engineering scaffold coatings and/or drug delivery are mentioned.
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Affiliation(s)
- Daniella L Morgado
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780, São Carlos 13560-970, Brazil.
| | - Bruno V M Rodrigues
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780, São Carlos 13560-970, Brazil.
| | - Erika V R Almeida
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780, São Carlos 13560-970, Brazil.
| | - Omar A El Seoud
- Institute of Chemistry, University of São Paulo, P.O. Box 26077, São Paulo 05513-970, Brazil.
| | - Elisabete Frollini
- Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780, São Carlos 13560-970, Brazil.
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Brandt WC, Silva CG, Frollini E, Souza-Junior EJC, Sinhoreti MAC. Dynamic mechanical thermal analysis of composite resins with CQ and PPD as photo-initiators photoactivated by QTH and LED units. J Mech Behav Biomed Mater 2013; 24:21-9. [PMID: 23714138 DOI: 10.1016/j.jmbbm.2013.04.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/02/2013] [Accepted: 04/07/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the thermal and mechanical properties of the composite resins containing the photo-initiators camphorquinone (CQ) and/or phenyl-propanodione (PPD) when photoactivated with halogen lamp (XL2500/3M-ESPE), monowave (UltraBlueIS/DMC) and polywave (UltraLume5/Ultradent) LED units. MATERIALS AND METHODS A blend of BisGMA, UDMA, BisEMA and TEGDMA was prepared with the same wt% of photo-initiators CQ and/or PPD and 65wt% of silaneted filler particles. Compression strength (CS), diametral tensile strength (DTS) and diametral modulus (DM) were tested. Thermogravimetric analysis (TGA) was made and the lost residual monomer were verified. Dynamic mechanical thermal analysis (DMTA) was used for to analyze the glass transition temperature (Tg) and the storage modulus in 37°C. Degree of conversion (DC) was accomplished in the same samples of DMA using middle-infrared spectroscopy (mid-IR). RESULTS CQ, CQ/PPD and PPD obtained the same results for all mechanical properties (CS, DTS and DM), lost residual monomer and storage modulus in 37°C, regardless LCU used. The results of Tg showed that the combination PPD-UltraLume5 produced the highest values. DC showed that the combination CQ-UltraLume5 resulted in the highest values and PPD-XL2500 in the lowest DC values. CONCLUSION The study shows that PPD is not only effective photosensitizers, but also photocrosslinking agents for dental composite resins with a similar efficiency to CQ.
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Affiliation(s)
- William Cunha Brandt
- School of Dentistry, University of Santo Amaro-UNISA, Prof. Eneas de Siqueira Neto, 340 São Paulo, SP, Brazil.
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Castro DO, Frollini E, Marini J, Ruvolo-Filho A. Preparação e caracterização de biocompósitos baseados em fibra de curauá, biopolietileno de alta densidade (BPEAD) e polibutadieno líquido hidroxilado (PBHL). Polímeros 2013. [DOI: 10.1590/s0104-14282013005000002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neste trabalho, foram utilizadas fibras de curauá como reforço de matriz termoplástica de biopolietileno de alta densidade. O polietileno foi obtido por polimerização de eteno, gerado do etanol de cana de açúcar. Este polímero é também chamado de biopolietileno (BPEAD), por ser preparado a partir de material oriundo de fonte natural. Desta forma, pretendeu-se contribuir para desenvolver materiais que, dentre outras propriedades, causem menor emissão de CO2 para a atmosfera na sua produção, utilização e substituição, comparativamente a outros materiais. Adicionalmente, polibutadieno líquido hidroxilado (PBHL) foi acrescentado à formulação do compósito, visando a um aumento na resistência à propagação da trinca durante impacto. Os compósitos e as fibras foram caracterizados por várias técnicas, tais como microscopia eletrônica de varredura (MEV), Calorimetria Exploratória Diferencial (DSC), Termogravimetria (TG), além da caracterização dos compósitos quanto à Análise Térmica Dinâmico-Mecânica (DMTA), propriedades mecânicas (impacto e flexão) e absorção de água. A presença das fibras de curauá diminuiu algumas propriedades do BPEAD, como resistência ao impacto. A análise de DMTA mostrou que as fibras geram material mais rígido. Pode-se considerar que a introdução de PBHL na formulação do material foi eficiente, levando a uma resistência ao impacto do compósito BPEAD/PBHL/Fibra maior do que a do compósito BPEAD/Fibra.
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Ramires EC, de Oliveira F, Frollini E. Composites based on renewable materials: Polyurethane-type matrices from forest byproduct/vegetable oil and reinforced with lignocellulosic fibers. J Appl Polym Sci 2013. [DOI: 10.1002/app.38934] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Frollini E. Revista Polímeros: Modificações visando o aprimoramento constante. Polímeros 2013. [DOI: 10.1590/s0104-14282013000100002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lacerda TM, Zambon MD, Frollini E. Effect of acid concentration and pulp properties on hydrolysis reactions of mercerized sisal. Carbohydr Polym 2012; 93:347-56. [PMID: 23465940 DOI: 10.1016/j.carbpol.2012.10.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 10/15/2012] [Indexed: 11/19/2022]
Abstract
The influence of sulfuric acid concentration (H2SO4 5-25%, 100°C), crystallinity and fibers size on the hydrolysis reaction of sisal pulps were investigated, with the goal of evaluating both the liquor composition, as an important step in the production of bioethanol, and the residual non-hydrolyzed pulp, to determine its potential application as materials. Aliquots were withdrawn from the reaction media, and the liquor composition was analyzed by HPLC. The residual non-hydrolyzed pulps were characterized by SEM, their average molar mass and crystallinity index, and their size distribution was determined using a fiber analyzer. Sulfuric acid 25% led to the highest glucose content (approximately 10gL(-1)), and this acid concentration was chosen to evaluate the influence of both the fiber size and crystallinity of the starting pulp on hydrolysis. The results showed that fibers with higher length and lower crystallinity favored glucose production in approximately 12%, with respect to the highly crystalline shorter fibers.
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Affiliation(s)
- Talita M Lacerda
- Macromolecular Materials and Lignocellulosic Fibers Group, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970, São Carlos, São Paulo, Brazil
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Frollini E. [NO TITLE AVAILABLE]. Polímeros 2012. [DOI: 10.1590/s0104-14282012000300002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ramos LA, Morgado DL, Gessner F, Frollini E, Seoud OAE. A physical organic chemistry approach to dissolution of cellulose: effects of cellulose mercerization on its properties and on the kinetics of its decrystallization. ARKIVOC 2011. [DOI: 10.3998/ark.5550190.0012.734] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
Cellulose acetates with different degrees of substitution (DS, from 0.6 to 1.9) were prepared from previously mercerized linter cellulose, in a homogeneous medium, using N,N-dimethylacetamide/lithium chloride as a solvent system. The influence of different degrees of substitution on the properties of cellulose acetates was investigated using thermogravimetric analyses (TGA). Quantitative methods were applied to the thermogravimetric curves in order to determine the apparent activation energy (Ea) related to the thermal decomposition of untreated and mercerized celluloses and cellulose acetates. Ea values were calculated using Broido's method and considering dynamic conditions. Ea values of 158 and 187 kJ mol-1 were obtained for untreated and mercerized cellulose, respectively. A previous study showed that C6OH is the most reactive site for acetylation, probably due to the steric hindrance of C2 and C3. The C6OH takes part in the first step of cellulose decomposition, leading to the formation of levoglucosan and, when it is changed to C6OCOCH3, the results indicate that the mechanism of thermal decomposition changes to one with a lower Ea. A linear correlation between Ea and the DS of the acetates prepared in the present work was identified.
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Abstract
Celulose de linter foi acetilada, visando obter acetatos de celulose com diferentes Graus de Substituição (GS) em meio homogêneo, usando cloreto de lítio/N,N-dimetilacetamida (LiCl/DMAc) como sistema de solvente, e anidrido acético como reagente acetilante. A agregação entre cadeias de celulose ou acetatos de celulose (GS 0,8, 1,5 e 2,0) em solução foi avaliada através de medidas viscosimétricas. Os resultados mostraram que a formação de agregados no sistema de solvente utilizado (LiCl/DMAc) é diferente para celulose e acetatos, e dependente da temperatura e do GS, no caso dos acetatos. Este trabalho corresponde à primeira etapa de um estudo em que se pretende preparar filmes de acetatos, assim como de acetatos reforçados com celulose, diretamente a partir de soluções destes em LiCl/DMAc. Os resultados apresentados permitem uma escolha melhor embasada do intervalo de concentração mais adequado para preparação de filmes, a partir de soluções de acetatos e celulose nesse sistema de solvente.
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Brandt WC, Schneider LFJ, Frollini E, Correr-Sobrinho L, Sinhoreti MAC. Effect of different photo-initiators and light curing units on degree of conversion of composites. Braz Oral Res 2010; 24:263-70. [DOI: 10.1590/s1806-83242010000300002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 05/17/2010] [Indexed: 11/22/2022] Open
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Ramires EC, Megiatto JD, Gardrat C, Castellan A, Frollini E. Valorization of an industrial organosolv-sugarcane bagasse lignin: Characterization and use as a matrix in biobased composites reinforced with sisal fibers. Biotechnol Bioeng 2010; 107:612-21. [DOI: 10.1002/bit.22847] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ramires EC, Megiatto Jr. JD, Gardrat C, Castellan A, Frollini E. Biocompósitos de matriz glioxal-fenol reforçada com celulose microcristalina. Polímeros 2010. [DOI: 10.1590/s0104-14282010005000016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glioxal pode ser obtido a partir de biomassa (como da oxidação de lipídeos) e não é tóxico ou volátil, tendo sido por isso utilizado no presente trabalho como substituto de formaldeído na preparação de resina fenólica do tipo novolaca, sendo usado como catalisador o ácido oxálico, que também pode ser obtido de fontes renováveis. A resina glioxal-fenol foi utilizada na preparação de compósitos reforçados com celulose microcristalina (CM, 30, 50 e 70% em massa), uma celulose com elevada área superficial. As imagens de microscopia eletrônica de varredura (MEV) das superfícies fraturadas demonstraram que os compósitos apresentaram boa interface reforço/matriz, consequência da elevada área superficial da CM e presença de grupos polares (hidroxilas) tanto na matriz como na celulose, o que permitiu a formação de ligações hidrogênio, favorecendo a compatibilidade entre ambas. A análise térmica dinâmico-mecânica (DMTA) demonstrou que todos os compósitos apresentaram elevado módulo de armazenamento à temperatura ambiente. Além disso, o compósito reforçado com 30% de CM apresentou baixa absorção de água, comparável à do termorrígido fenólico, que é utilizado em escala industrial. Os resultados demonstraram que compósitos com boas propriedades podem ser preparados usando elevada proporção de materiais obtidos de biomassa.
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Ramires EC, Megiatto JD, Gardrat C, Castellan A, Frollini E. Biobased composites from glyoxal-phenolic resins and sisal fibers. Bioresour Technol 2010; 101:1998-2006. [PMID: 19880315 DOI: 10.1016/j.biortech.2009.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 10/01/2009] [Accepted: 10/01/2009] [Indexed: 05/22/2023]
Abstract
Lignocellulosic materials can significantly contribute to the development of biobased composites. In this work, glyoxal-phenolic resins for composites were prepared using glyoxal, which is a dialdehyde obtained from several natural resources. The resins were characterized by (1)H, (13)C, 2D, and (31)P NMR spectroscopies. Resorcinol (10%) was used as an accelerator for curing the glyoxal-phenol resins in order to obtain the thermosets. The impact-strength measurement showed that regardless of the cure cycle used, the reinforcement of thermosets by 30% (w/w) sisal fibers improved the impact strength by one order of magnitude. Curing with cycle 1 (150 degrees C) induced a high diffusion coefficient for water absorption in composites, due to less interaction between the sisal fibers and water. The composites cured with cycle 2 (180 degrees C) had less glyoxal resin coverage of the cellulosic fibers, as observed by images of the fractured interface observed by SEM. This study shows that biobased composites with good properties can be prepared using a high proportion of materials obtained from natural resources.
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Affiliation(s)
- Elaine C Ramires
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970 São Carlos, SP, Brazil
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Botaro VR, Siqueira G, Megiatto JD, Frollini E. Sisal fibers treated with NaOH and benzophenonetetracarboxylic dianhydride as reinforcement of phenolic matrix. J Appl Polym Sci 2010. [DOI: 10.1002/app.31113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ciacco GT, Morgado DL, Frollini E, Possidonio S, El Seoud OA. Some aspects of acetylation of untreated and mercerized sisal cellulose. J BRAZIL CHEM SOC 2010. [DOI: 10.1590/s0103-50532010000100012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Cerrutti BM, Lamas JC, De Britto D, Campana Filho SP, Frollini E. Derivatives of biomacromolecules as stabilizers of aqueous alumina suspensions. J Appl Polym Sci 2010. [DOI: 10.1002/app.31362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Ciacco GT, Ramos LA, Frollini E, Ass BAP. Sisal, Sugarcane Bagasse and Microcrystalline Celluloses: Influence of the Composition of the Solvent System N,NDimethylacetamide /Lithium Chloride on the Solubility and Acetylation of these Polysaccharides. e-Polymers 2008. [DOI: 10.1515/epoly.2008.8.1.226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe present work describes an investigation concerning the acetylation of celluloses extracted from short-life-cycle plant sources (i.e. sugarcane bagasse and sisal fiber) as well as microcrystalline cellulose. The acetylation was carried out under homogeneous conditions using the solvent system N,Ndimethylacetamide/ lithium chloride. The celluloses were characterized, and the characterizations included an evaluation of the amount of hemicellulose present in the materials obtained from lignocellulosics sources (sugarcane and sisal). The amount of LiCl was varied and its influence on the degree of acetate substitution was analyzed. It was found that the solvent system composition and the nature of the cellulose influenced both the state of chain dissolution and the product characteristics. The obtained results demonstrated the importance of developing specific studies on the dissolution process as well as on the derivatization of celluloses from various sources.
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Affiliation(s)
- Gabriela T. Ciacco
- 1Instituto de Química de São Carlos, Universidade de São Paulo, C. P. 780, CEP 13560-970, São Carlos, SP, Brazil; fax: +55 16 3373 9952
| | - Ludmila A. Ramos
- 1Instituto de Química de São Carlos, Universidade de São Paulo, C. P. 780, CEP 13560-970, São Carlos, SP, Brazil; fax: +55 16 3373 9952
| | - Elisabete Frollini
- 1Instituto de Química de São Carlos, Universidade de São Paulo, C. P. 780, CEP 13560-970, São Carlos, SP, Brazil; fax: +55 16 3373 9952
| | - Beatriz A. P. Ass
- 1Instituto de Química de São Carlos, Universidade de São Paulo, C. P. 780, CEP 13560-970, São Carlos, SP, Brazil; fax: +55 16 3373 9952
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Megiatto JD, Silva CG, Rosa DS, Frollini E. Sisal chemically modified with lignins: Correlation between fibers and phenolic composites properties. Polym Degrad Stab 2008. [DOI: 10.1016/j.polymdegradstab.2008.03.011] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Oliveira FB, Gardrat C, Enjalbal C, Frollini E, Castellan A. Phenol–furfural resins to elaborate composites reinforced with sisal fibers—Molecular analysis of resin and properties of composites. J Appl Polym Sci 2008. [DOI: 10.1002/app.28312] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Megiatto JD, Hoareau W, Gardrat C, Frollini E, Castellan A. Sisal fibers: surface chemical modification using reagent obtained from a renewable source; characterization of hemicellulose and lignin as model study. J Agric Food Chem 2007; 55:8576-84. [PMID: 17867642 DOI: 10.1021/jf071682d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Sisal fibers have one of the greatest potentials among other lignocellulosic fibers to reinforce polymer matrices in composites. Sisal fibers have been modified to improve their compatibility with phenolic polymer matrices using furfuryl alcohol (FA) and polyfurfuryl alcohols (PFA) that can be obtained from renewable sources. The modification corresponded first to oxidation with ClO 2, which reacts mainly with guaiacyl and syringyl units of lignin, generating o- and p-quinones and muconic derivatives, followed by reaction with FA or PFA. The FA and PFA modified fibers presented a thin similar layer, indicating the polymer character of the coating. The untreated and treated sisal fibers were characterized by (13)C CP-MAS NMR spectrometry, thermal analysis, and scanning electron microscopy. Furthermore, for a better understanding of the reactions involved in the FA and PFA modifications, the sisal lignin previously extracted was also submitted to those reactions and characterized. The characterization of isolated lignin and hemicellulose provides some information on the chemical structure of the main constitutive macrocomponents of sisal fibers, such information being scarce in the literature.
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Affiliation(s)
- Jackson D Megiatto
- Instituto de Química de São Carlos, Universidade de São Paulo, USP, C.P. 780, CEP 13560-970 São Carlos, SP, Brazil
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Megiatto JD, Oliveira FB, Rosa DS, Gardrat C, Castellan A, Frollini E. Renewable Resources as Reinforcement of Polymeric Matrices: Composites Based on Phenolic Thermosets and Chemically Modified Sisal Fibers. Macromol Biosci 2007; 7:1121-31. [PMID: 17676656 DOI: 10.1002/mabi.200700083] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Lignocellulosic materials can significantly contribute to the development of composites, since it is possible to chemically and/or physically modify their main components, cellulose, hemicelluloses and lignin. This may result in materials more stable and with more uniform properties. It has previously been shown that chemically modified sisal fibers by ClO(2) oxidation and reaction with FA and PFA presented a thin coating layer of PFA on their surface. FA and PFA were chosen as reagents because these alcohols can be obtained from renewable sources. In the present work, the effects of the polymeric coating layer as coupling agent in phenolic/sisal fibers composites were studied. For a more detailed characterization of the fibers, IGC was used to evaluate the changes that occurred at the sisal fibers surface after the chemical modifications. The dispersive and acid-base properties of untreated and treated sisal fibers surfaces were determined. Biodegradation experiments were also carried out. In a complementary study, another PFA modification was made on sisal fibers, using K2Cr2O(7) as oxidizing agent. In this case the oxidation effects involve mainly the cellulose polymer instead of lignin, as observed when the oxidation was carried out with ClO(2). The SEM images showed that the oxidation of sisal fibers followed by reaction with FA or PFA favored the fiber/phenolic matrix interaction at the interface. However, because the fibers were partially degraded by the chemical treatment, the impact strength of the sisal-reinforced composites decreased. By contrast, the chemical modification of fibers led to an increase of the water diffusion coefficient and to a decrease of the water absorption of the composites reinforced with modified fibers. The latter property is very important for certain applications, such as in the automotive industry.
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Affiliation(s)
- Jackson D Megiatto
- Instituto de Química de São Carlos, Universidade de São Paulo, USP, C.P. 780, CEP 13560-970 São Carlos, SP, Brazil
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