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Biobased composites from tannin-phenolic polymers reinforced with coir fibers

BARBOSA JR., Vilmar; RAMIRES, Elaine Cristina; RAZERA, Ilce Aiko Tanaka; FROLLINI, Elisabete
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
502.83785%
Tannin-phenolic polymers prepared using tannin, a macromolecule obtained from natural sources, were used in the preparation of composites reinforced with coir fibers. The composites based on tannin-phenolic polymers (50% (w/w) of tannin as substitute of the phenol) were prepared using the coir fibers as reinforcement (30-70% (w/w), 3.0-6.0 cm, randomly distributed). The Izod impact strength of the composites showed an improvement in this property due to the incorporation of coir fibers in the tannin-phenolic matrices. The SEM images showed excellent adhesion at the fiber/matrix interface. The coir fiber had bundles regularly spaced, which enhanced the diffusion of the resin into the fiber. In addition, the high lignin content of this fiber results in a high concentration of aromatic rings, which increased the compatibility with the matrix. The values of the diffusion coefficient of water, determined using Fick`s laws, show that there was no correlation between the fiber percentage and the water diffusion. The DMTA curves showed that the storage moduli of the composites reinforced with coir fibers were considerably higher than that of the thermoset, and the increase in the proportion of fibers led to a proportional increase in the storage moduli of these materials. The biobased composites obtained have potential for non-structural applications...

Biobased composites from glyoxal-phenolic resins and sisal fibers

RAMIRES, Elaine C.; MEGIATTO JR., Jackson D.; GARDRAT, Christian; CASTELLAN, Alain; FROLLINI, Elisabete
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
499.92227%
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, (2)D, 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. (C) 2009 Elsevier Ltd. All rights reserved.; CAPES/COFECUB[422/03/05]; COFECUB; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CNPq; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); FAPESP

Tanino como macromonômero na síntese de polímeros fenólicos visando a preparação de compósitos reforçados com material de origem vegetal; Tannin as substitute of phenols in the formulation of phenolic resins for the processing of composites reinforced with material from renewable source

Barbosa Junior, Vilmar
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/03/2007 PT
Relevância na Pesquisa
306.16842%
No presente trabalho, tanino (macromolécula de origem natural) foi utilizado como substituinte de fenol na formulação de matriz fenólica usada na preparação de compósitos, o que é possível devido à presença de anéis fenólicos sua estrutura. Os compósitos de matriz taninofenólica (50% em massa de tanino) apresentaram propriedades mecânicas superiores aquelas dos compósitos de matriz fenólica, quando reforçados pelo mesmo tipo de fibra, mostrando que a substituição de material obtido em larga escala a partir de fonte fóssil (fenol) é viável e pode ser feita por material obtido de fonte renovável (tanino) sem comprometimento de propriedades. Ainda, avaliou-se para propriedades de compósitos com diferentes tipos de reforços (fibras e cargas) através de caracterizações via análise térmica (TG e DSC), análise dinâmico-mecânica, espectroscopia na região do infravermelho, resistência ao impacto, absorção de água e microscopia eletrônica de varredura. Os ensaios de resistência ao impacto indicaram uma melhora de propriedades mecânicas quando da incorporação de fibras vegetais (juta e coco) nos termorrígidos fenólico e taninofenólico, além de mostrar que as fibras de juta reforçam as matrizes taninofenólicas mais eficientemente que as fibras de coco. As cascas da árvore de Acácia Negra...

Natural fibers based composites - Technical and social issues

Leao, A.; Sartor, S. M.; Caraschi, José Cláudio
Fonte: Taylor & Francis Ltd Publicador: Taylor & Francis Ltd
Tipo: Artigo de Revista Científica Formato: 161-177
ENG
Relevância na Pesquisa
440.11754%
Brazil is the only country in South America to have an automotive supplier sector based on natural fibers. New opportunities are arising due to an increase demand by the car makers in applying natural fibers in their parts. Several crop fibers have been developed in Brazil. Among them can be listed caroa, piacava, pupunha, mutum and others of regional application. For the automotive industry, which requires large quantities with uniform quality, the alternatives are sisal (170,000 ton/yr), curaua (150 ton/yr in 2003), malva, 200 ton/yr; Brazil is the single largest producer country of sisal, and commercially, the only one in curaua. For South America, the alternatives are fique in Colombia, abaca in equator, flax in Argentina and curaua in Venezuela. It must be understood by the target countries of drugs, is that crop fiber can be an economic alternative to coca in the Andes region, therefore an instrument of land reform and drug reduction plantations. Several companies have a strong program of apply natural fibers based components in their products: Volkswagen do Brazil, DaimlerChrysler, General Motors do Brazil. Among their suppliers can be listed companies such Pematec (curaua), Toro (sisal, coir and jute), Incomer (sisal and jute)...

Fibras naturais como matéria-prima para a produção de carvão ativado; Natural fibers as raw material for the production of activated carbon

Carla Fabiana Scatolim Rombaldo
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/06/2015 PT
Relevância na Pesquisa
427.09906%
As fibras obtidas diretamente de fonte animal, mineral e vegetal são definidas como fibras naturais, sendo as mais comuns: a lã, o linho, o rami, o sisal, a juta, entre outras. Essas fibras têm uma importância social muito forte em países tropicais, especialmente na geração de empregos na zona rural e em áreas economicamente deprimidas. As fibras naturais, em sua maioria, são leves, resistentes, não abrasivas, renováveis, biodegradáveis e recicláveis, características que permitem competir com outros materiais artificiais que tenham problemas de disponibilidade ou ambientais. Além dos compósitos desenvolvidos com fibras naturais, existem ainda os carvões ativados que se destacam como um material com elevada porosidade e alta capacidade de adsorção, tanto em fase liquida quanto em fase gasosa. Visando o aproveitamento de recursos naturais disponíveis no território nacional e buscando alternativas que sejam economicamente viáveis para a produção de carvão ativado (CA), o presente trabalho teve como objetivo geral utilizar as fibras de juta e as fibras de sisal como matérias-primas para a produção de CA. Os CAs produzidos foram testados para a remoção de benzeno em solução aquosa. A produção do CA foi baseada na carbonização e na ativação física com CO2 e vapor d¿água. Para avaliar a evolução da estrutura porosa dos CAs obtidos foi utilizada a técnica de adsorção de N2 a 77K. Os resultados indicaram a possibilidade de produzir um material poroso com uma combinação de estrutura micro e mesoporosa...

Efeito do tratamento de superfície em fibras de juta no comportamento mecânico de compósitos de matriz epóxi

Pires, Eduardo Nascimento
Fonte: Florianópolis, SC Publicador: Florianópolis, SC
Tipo: Dissertação de Mestrado Formato: 119 f.| il., grafs., tabs.
POR
Relevância na Pesquisa
320.96129%
Dissertação (mestrado) - Universidade Fderal de Santa Catarina, Centro Tecnologico. Programa de Pós-Graduação em Ciência e Engenharia de Materiais; A preocupação mundial da sociedade moderna em diminuir o impacto ambiental e encontrar soluções para o esgotamento de recursos naturais não renováveis vem incentivando a pesquisa e desenvolvimento de materiais sustentáveis. As fibras naturais inserem-se nesse contexto como uma alternativa para a fabricação de materiais compósitos. Este trabalho tem como objetivo avaliar a eficiência das diferentes formas de tratamento de superfície em fibras de juta no desempenho mecânico de materiais compósitos com matriz de resina epóxi. As fibras foram modificadas superficialmente a partir de solução de hidróxido de sódio e hidróxido de sódio seguido por agente silano, e caracterizadas por microscopia eletrônica e ótica, espectrometria no infravermelho com transformada de Fourier (FTIR), resistência à tração e densidade. A partir dos espectros de FTIR das fibras tratadas e não tratadas, foi possível observar modificações em sua estrutura química. Os resultados de resistência à tração e microscopia eletrônica mostraram manutenção da propriedade mecânica e aumento da rugosidade das fibras tratadas...

Experimental study on natural fiber composites for strengthening of masonry

Codispoti, R.; Oliveira, Daniel V.; Fangueiro, Raúl; Olivito, R.; Lourenço, Paulo B.
Fonte: AIAS Publicador: AIAS
Tipo: Conferência ou Objeto de Conferência
Publicado em 21/12/2012 ENG
Relevância na Pesquisa
277.39277%
In the present paper the first results obtained from a vast experimental investigation carried out on natural fiber composite materials (flax, hemp, jute, sisal and coir) are reported. Tensile tests on single yarns and fabrics have been carried out according to the current standards. Two types of matrices have been used: polymeric and mortar-based matrices. Therefore, the composites materials NFRP (Natural Fiber Reinforced Polymer) and NFRG (Natural Fiber Reinforced Grout) have been obtained. A new fiber placement technology has been studied, the so-called "braiding technology", in order to increase the mechanical properties of the natural non-impregnated materials. The results obtained, were compared with those of the most common composites systems (CFRP and GFRP).

Processing and properties of natural fibers reinforced thermoplastic and thermosseting composites

Silva, J. F.; Nunes, J. P.; Duro, A. C.; Castro, B. F.
Fonte: Canadian Association for Composite Structures and Materials (CACSMA) Publicador: Canadian Association for Composite Structures and Materials (CACSMA)
Tipo: Conferência ou Objeto de Conferência
Publicado em 29/07/2013 ENG
Relevância na Pesquisa
396.10957%
In this work, three different natural fibers were studied and characterized, using optical and SEM microscopy. Woven fabrics of those reinforcement fibers were used to reinforce polyester and epoxy matrices and produce composite plates by vacum lay-up. Also, using an experimental piston blender equipment, long fiber reinforced PLA (LFT) composites were manufactured by hot compression molding. All different obtained composite plates were submitted to mechanical testing in order to determine relevant mechanical proprieties.; Fundação para a Ciência e a Tecnologia (FCT)

Development and assessment to environmentally friendly natural fiber composites

Nunes, J. P.; Castro, B. F.; Duro, A. C.; Silva, J. F.; Oliveira, Luís
Fonte: Tecminho / Universidade do Minho Publicador: Tecminho / Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em 09/06/2013 ENG
Relevância na Pesquisa
424.88523%
Two different types of natural fibers (jute and sisal) were studied and characterized, using optical microscopy, pycnometry density, single filament and linear density tests. Jute fibers were processed into composite parts from woven fabrics raw-material and sisal fibers were also processed into final composite componentes but in the form of chopped mat. Those fibers were used to reinforce polyester and epoxy matrices and therefore produce composite plates by resin infusion molding. Finally, the final obtained composite plates were submitted to mechanical testing, in order to assess their relevant mechanical properties.; Fundação para a Ciência e a Tecnologia (FCT)

Experimental behavior of natural fiber-based composites used for strengthening masonry structures

Codispoti, Rosamaria; Oliveira, Daniel V.; Fangueiro, Raúl; Lourenço, Paulo B.; Olivito, Renato S.
Fonte: Hindawi Publicador: Hindawi
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
287.53105%
This paper deals with the experimental characterization of the tensile behavior of fiber-based composites and flexural strength of natural fiber reinforced polymer (NFRP) sheets externally glued on masonry bricks, in terms of load capacity and stress distribution along the bonded length. The bricks adopted for this experimentation are solid clay bricks, typically used in ancient masonry structures. Non-impregnated and impregnated flax, hemp, jute and sisal fibers were examined. Two types of matrices have been used: polymer matrices and mortar- based matrices. Composite materials defined as NFRP (Natural Fiber Reinforced Polymer) and NFRG (Natural Fiber Reinforced Grout) were obtained.

Estudo da degradação de geotêxteis em fibra natural; Study of the degradation of natural fiber geotextiles

Costa, José Eduardo Gonçalves
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Trabalho de Conclusão de Curso
Publicado em //2013 POR
Relevância na Pesquisa
317.20742%
Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Construções); A sociedade atual sente cada vez mais a necessidade de procurar soluções eficientes e sustentáveis para os problemas do dia-a-dia. Sendo o setor da construção civil um dos grandes responsáveis pela exploração de recursos e emissão de gases poluentes, fruto da sua atividade, torna-se necessário a alteração de algumas das práticas atuais. Os geotêxteis usados em diversas aplicações, como por exemplo, controlo da erosão de taludes, reforço ou drenagem de solos em obras de engenharia são quase exclusivamente compostos por materiais sintéticos. A consideração de geotêxteis de fibras naturais, especialmente quando o período funcional requerido a um geotêxtil é de apenas alguns meses, torna-se a solução ideal devido ao facto de estes serem biodegradáveis e constituídos por recursos renováveis, sendo ambientalmente mais sustentáveis que os seus semelhantes sintéticos. Esta dissertação pretende contribuir para o aprofundamento do conhecimento sobre a viabilidade da consideração de fibras naturais de origem vegetal como geotêxteis, nomeadamente o seu comportamento mecânico e estrutura fibrosa...

HRP-mediated polyacrylamide graft modification of raw jute fabric

Liu, Ruirui; Dong, Aixue; Fan, Xuerong; Wang, Qiang; Yu, Yuanyuan; Paulo, Artur Cavaco
Fonte: Elsevier BV Publicador: Elsevier BV
Tipo: Artigo de Revista Científica
Publicado em /06/2015 ENG
Relevância na Pesquisa
521.60902%
The horseradish peroxidase (HRP)/hydrogen peroxide system can catalyze the free-radical polymerization of aromatic compounds such as lignins. In this study, to improve the hydrophilicity of lignin-rich jute fabrics, acrylamide (AM) was grafted onto their surface by HRP-mediated oxidative polymerization. The resulting AM-lignin graft polymer in jute fibers, from which the lignin was removed by extracting with dioxane, was characterized by gel permeation chromatography, elemental analysis, matrix-assisted laser desorption/ionization mass spectromrtry, nuclear magnetic resonance, scanning electron microscopy, and Fourier transform infrared spectroscopy. The results show that AM was grafted to the jute fiber by HRP. Furthermore, the hydrophilicity of the fabrics was determined in terms of wetting time, balance moisture regain, and static contact angle. Compared to the control sample, the wetting time, balance moisture regain, and static contact angle of the grated fabrics varied from 11.62 min to 7.45 min, from 9.78% to 10.40%, and from 122.30° to 92.84°, respectively, indicating that the hydrophilicity of the raw jute fabric improved. The modification conditions of the HRP-catalyzed AM-grafting reaction were optimized in terms of the nitrogen content of the jute fabrics.

Acoustical behavior of hybrid composite sandwich panels

Patinha, Sérgio; Cunha, Fernando Eduardo Macedo; Fangueiro, Raúl; Rana, Sohel; Prego, Fernando
Fonte: Trans Tech Publications Publicador: Trans Tech Publications
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
Relevância na Pesquisa
287.53105%
This paper deals with the characterization of acoustic insulation behaviour of hybrid sandwich composite panels for application in modular house construction. These sandwich panels are a sustainable, light-weight and durable solution, since are based on natural fibers structure impregnated with a thermosetting polymer. In this way, three different types of hybrid composite panels containing polyurethane core and laminated composite skins were produced and analyzed, varying the composition of laminates. The composite laminates of the prototypes were produced using a vacuum infusion technique and were composed of glass and jute fibers, impregnated with a polyester resin. The solutions developed were compared with a standard, composed of plasterboards having different thicknesses and used for thermal and acoustic insulation. Acoustic insulation characterization was performed on specimens with 220x220 mm size in a sound proof acoustic chamber. The tested sandwich panels showed promising results; however, their overall performance was lower as compared to the performance of standard solutions used for comparison. Nevertheless, the specific acoustic insulation performance, i.e. sound reduction per unit mass of material for the developed sandwich panels was significantly higher as compared to the standard materials...

Treatments of jute fibers aiming at improvement of fiber-phenolic matrix adhesion

Razera,Ilce Aiko Tanaka; Silva,Cristina Gomes da; Almeida,Érika Virgínia Raphael de; Frollini,Elisabete
Fonte: Associação Brasileira de Polímeros Publicador: Associação Brasileira de Polímeros
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
Relevância na Pesquisa
741.0636%
Composites based on a thermoset phenolic matrix and jute fibers were prepared and characterized. The fibers were alternatively treated with ionized air or aqueous alkaline solution (mercerization) with the aim of introducing changes in the morphology, dispersive component of surface free energy, γS D (estimated by Inverse Gas Chromatography, IGC) and the acid/base character of their surfaces, shown by their ANs/DNs ratio (estimated by IGC), and their degree of crystallinity. The final objective was to investigate the influence of these modifications on the adhesion at the jute fiber/phenolic matrix interface in the composites. The untreated jute fiber showed 50% crystallinity, γS D=18 mJ m- 2 and ANs/DNs= 0.9 (amphoteric surface), tensile strength = 460 MPa and maximum elongation = 0.7%, while the respective composite had an impact strength of 72.6 J m- 1. The treatments positively modified the fibers and the adhesion at the interface was better in the composites reinforced with treated fibers than with untreated fibers. The best set of results was exhibited by the fiber treated with 10% NaOH [46% crystallinity, γS D = 26 J m- 2 (phenolic matrix γS D = 32 J m- 2), ANs/DNs = 1.8 (surface predominantly acidic...

Diameter dependence of tensile strength by Weibull analysis: Part II jute fiber

Bevitori,A. B.; Silva,I.L.A. Da; Lopes,F.P.D.; Monteiro,S.N.
Fonte: Rede Latino-Americana de Materiais Publicador: Rede Latino-Americana de Materiais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
431.74727%
The jute fiber is one of the strongest lignocellulosic fibers with applications ranging from simple items such as fabrics and ropes to engineering composites for automobile parts and building panels. Like other lignocellulosic fibers, the jute may have an inverse strength dependence with its diameter. In principle, thinner jute fiber could be comparatively stronger and consequently more effective as a composite reinforcement. Therefore, an attempt to correlate the jute fiber strength obtained in tensile test with its corresponding diameter, precisely measured by means of a profile projector, was carried out. A Weibull statistical analysis confirmed the inverse dependence between the jute fiber tensile strength and the corresponding fiber diameter. Scanning electron microscopy observation of the fracture of selected ruptured fiber revealed possible mechanisms that could justify the strength/diameter inverse dependence.

Selection of high strength natural fibers

Monteiro,S.N.; Satyanarayana,K.G.; Ferreira,A.S.; Nascimento,D.C.O.; Lopes,F.P.D.; Silva,I.L.A.; Bevitori,A.B.; Inácio,W.P.; Bravo Neto,J.; Portela,T.G.
Fonte: Rede Latino-Americana de Materiais Publicador: Rede Latino-Americana de Materiais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
402.83785%
By means of dimensional selection of natural lignocellulosic fibers, based on precise diameter measurements, it was recently possible to obtain fibers with relatively higher tensile strength. The present article overviews works on the statistical evaluation, through the Weibull analysis, of the ultimate tensile stress of eight lignocellulosic fibers: sisal, ramie, curaua, jute, bamboo, coir, piassava and buriti. It is shown that, for all of these fibers, the tensile strength holds an inverse relationship with the fiber diameter. Statistically this relationship conforms to a hyperbolic type of analytical equation, which discloses the possibility of unusually high strength fibers to be selected in association with very small diameters. A structural analysis using scanning electron microscopy offered an explanation to the strengthening mechanisms responsible for the superior performance of these dimensionally selected fibers.

Fumigation of Jute Bags with Ethylene Oxide and Methyl Bromide to Eradicate Potato Ring Rot Bacteria1

Richardson, L. T.; Monro, H. A. U.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1962 EN
Relevância na Pesquisa
296.2768%
In a series of full-scale tests, the effectiveness of various fumigant treatments for the eradication of potato ring rot bacteria from bulk lots of contaminated jute bags was evaluated. Survival of these bacteria on infested sample fibers located at various positions within and around a tightly wired bale was determined quantitatively from the growth lag in a liquid medium as indicated by the rate of turbidity development.

THE MICROCRYSTALLINE STRUCTURE OF CELLULOSE IN CELL WALLS OF COTTON, RAMIE, AND JUTE FIBERS AS REVEALED BY NEGATIVE STAINING OF SECTIONS

Heyn, A. N. J.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/05/1966 EN
Relevância na Pesquisa
411.7256%
With a new technique of negative staining of sections, it has been possible to observe directly, in ultrathin sections under the electron microscope, the original microcrystalline and microfibrillar structure of cellulose as it occurs in living cells. This method has advantages over the study of isolated fibers used so far by others, in that the original arrangement of microfibrils is better preserved, and their collapse into larger fibrillar units is prevented. With this method, the cell walls of ramie, jute, and cotton fibers have been studied. The size (diameter, 25 to 40 A) and the longitudinal periodicity observed in the single microfibrils and the orientation and spatial arrangement of the microcrystallite within the microfibrils are found to correspond with the latest models derived by others from data obtained by indirect methods such as X-ray diffraction. The microfibril size of about 35 A, found by measuring these structures in sections, agrees with the latest conclusions reached by others in recent work with isolated fibrils.

Ballistic Test of Multilayered Armor with Intermediate Epoxy Composite Reinforced with Jute Fabric

Luz,Fernanda Santos da; Lima Junior,Edio Pereira; Louro,Luis Henrique Leme; Monteiro,Sergio Neves
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
521.60902%
Multilayered armors with a front ceramic followed by aramid fabric (Kevlar™) are currently used against high velocity ammunition. In these armors, a front ceramic layer that shatters and spalls the bullet is followed by an intermediate layer, usually plies of aramid fabric, which dissipates both the bullet and ceramic fragments energy. In the present work, the intermediate aramid fabric layer was replaced by an equal thickness layer of 30 vol% jute fabric reinforced epoxy composite. Ballistic impact test with 7.62 caliber ammunition revealed that both the plain epoxy and the jute fabric composite have a relatively similar performance of the Kevlar™ and also attended the NIJ standard for body protection. The energy dissipation mechanisms of jute fabric composite were analyzed by scanning electron microscopy and found to be the rupture of the brittle epoxy matrix as well as the interaction of the jute fibers with the post-impact fragments. This latter is the same mechanism recently disclosed for aramid fabric. However, the lightness and lower cost of the jute fabric composite are additional advantages that favor its substitution for the aramid fabric.

Jute/polypropylene composites: Effect of enzymatic modification on thermo-mechanical and dynamic mechanical properties

Ni, Xiaoyan; Dong, Aixue; Fan, Xuerong; Wang, Qiang; Yu, Yuanyuan; Cavaco-Paulo, Artur
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em /10/2015 ENG
Relevância na Pesquisa
421.60902%
In this study, a high-performance composite was prepared from jute fabrics and polypropylene (PP). In order to improve the compatibility of the polar fibers and the non-polar matrix, alkyl gallates with different hydrophobic groups were enzymatically grafted onto jute fabric by laccase to increase the surface hydrophobicity of the fiber. The grafting products were characterized by FTIR. The results of contact angle and wetting time showed that the hydrophobicity of the jute fabrics was improved after the surface modification. The effect of the enzymatic graft modification on the properties of the jute/PP composites was evaluated. Results showed that after the modification, tensile and dynamic mechanical properties of composites improved, and water absorption and thickness swelling clearly decreased. However, tensile properties drastically decreased after a long period of water immersion. The thermal behavior of the composites was evaluated by TGA/DTG. The fiber-matrix morphology in the modified jute/PP composites was confirmed by SEM analysis of the tensile fractured specimens.; This work was financially supported by the National Natural Science Foundation of China (51173071), the Program for New Century Excellent Talents in University (NCET-12-0883)...