EFEITO DA INCORPORAÇÃO DE FIBRAS DE COCO NO COMPORTAMENTO DINÂMICO-MECÂNICO DE COMPÓSITOS COM MATRIZ POLIÉSTER
EFFECT OF COIR FIBER INCORPORATION IN DYNAMIC MECHANIC BEHAVIOR OF POLYESTER- MATRIX COMPOSITES
Monteiro, Sérgio Neves; Rodriguez, Rubén Jesus S.; Lopes, Felipe Perissé D.; Sores, Bluma Guenther
http://dx.doi.org/10.4322/tmm.00502009
Tecnol. Metal. Mater., vol.5, n2, p.111-115, 2008
Resumo
Realizou-se um estudo da variação com a temperatura dos parâmetros dinâmico-mecânicos de compósitos com matriz poliéster incorporada com fibras de coco. Diferentes percentagens em peso de fibras de coco, até 40%, foram misturadas com resina poliéster ortoftálica e, após prensagem, curada por 24 horas à temperatura ambiente. Ensaios dinâmico-mecânicos (DMA) foram realizados para se obter os módulos de armazenamento e perda, bem como a tangente delta para cada tipo de compósito com diferentes quantidades de fibra de coco. Os resultados desses parâmetros revelam que a incorporação de fibra de coco diminui a rigidez viscoelástica do compósito com matriz poliéster. Esta redução na rigidez está associada à baixa tensão interfacial, o que dificulta a transferência de esforços mecânicos da matriz para a fibra. Ocorrem também modificações na temperatura de transição vítrea e no pico α de relaxação com a incorporação de fibras de coco. Em particular, o amortecimento do compósito que está relacionado ao valor da tangente delta, diminui a quantidade de fibra incorporada pelo fato de somente parte da tensão aplicada deformar a interface fibra/matriz.
Palavras-chave
Fibra vegetal, Compósitos, Matriz poliéster, Comportamento, Temperatura de transição
Abstract
A study on the temperature variation of the dynamic-mechanical parameters of polyester matrix composites incorporated with continuous coir fibers was carried out. Different weight percentages, up to 40 wt.% of coir fibers, were mixed with orthophtalic polyester resin and, after press-molding, cured for 24 hours at room temperature. Dynamic-mechanical, DMA, tests were conducted to obtain the storage modulus and the loss modulus as well as the tangent delta for each type of composite with different amounts of coir fibers. The DMA results revealed that the incorporation of coir fiber decreases the viscoelastic stiffness of the composite with polyester matrix. This reduction in stiffness is associated with a low interfacial shear stress, which makes it difficult for the mechanical load transfer from the matrix to the fiber. Modifications in the glass transition temperature and in the a relaxation peak also occurred with the amount of incorporated coir fiber. In particular, the damping response of the composite, associated with the value of the tangent delta, decreases with the amount of incorporated fiber owing to the fact that only part of the applied stress was used to deform the fiber/matrix interface.
Keywords
Coir fiber, Polyester composites, Dynamic-mechanical behavior, Glass transition temperature
References
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4 ROUT, J.; MISRA, M.; TRIPATHY, S.S.; NAYAK, S.K.; MOHANTY, A.K. The influence of fibre treatment on the performance of coir-polyester composites. Composites Science and Technology, v. 61, n. 9, p. 1303-10, Jul. 2001.
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11 MONTEIRO, S.N.; TERRONES, L.A.H.; LOPES, F.P.D.; D’ALMEIDA, J.R.M., Mechanical strength of polyester matrix composites reinforced with coconut fiber wastes. Revista Matéria, v. 10, n. 4, p. 571-6, Oct. 2005.
12 MONTEIRO, S.N.; TERRONES, L.A.H.; CARVALHO, E.A.; D’ALMEIDA, J.R.M. Efeito da interface fibra/matriz sobre a resistência de compósitos poliméricos reforçados com fibras de coco, Revista Matéria, v. 11, n. 4, p. 395-402, Oct. 2006.
13 MONTEIRO, S.N.; TERRONES, L.A.H.; D’ALMEIDA, J.R.M.; OLIVEIRA, L.B.. Aplicações tecnológicas para compósitos poliméricos de mantas de fibra de coco. In: CONGRESSO ANUAL DA ABM, 60., 2005, Belo Horizonte. Anais... São Paulo: ABM, 2005. p. 1540-8.
14 RAY, D.; SARKAR, B.K.; DAS, S.; RANA, A.K. Dynamic mechanical and thermo analysis of vinylester - resin – matrix composites reinforced with untreated and alkali-treated jute fibres. Composites Science and Technology, v. 62, n. 7-8, p. 911-7, Jun. 2002.
15 MOHANTY, S.; VERMA, S.K; NAYAK, S.K. Dynamic mechanical and thermal properties of MAPE treated jute/HDPE composites. Composites Science and Technology, v. 66, n. 3-4, p. 538-47, Mar. 2006.
16 KUBAT, J.; RIODAHL, M.; WELANDER, M. Characterization of interfacial interactions in high density polyethylene filled with glass spheres using dynamic mechanical analysis. Journal of Applied Polymer Science, v. 39, n. 7, p. 1527-39, Apr. 1990.
17 BIKIARIS, D.; MATZINOS, P.; PRINOS, J.; FLARIS, V.; LARENA, A.; PANAYIOTOU, C. Use of silanes and copolymers as adhesion promoters in glass fibre/polyethylene composites. Journal of Applied Polymer Science, v. 80, n. 14, p. 2877-8, Jun. 2001.
18 VAJRASTHIRA, C.; AMORNSAKCHAI, T.; LIMCHAROEN, B. Fibre-matrix interaction in aramid short fibre reinforced thermoplastic composites. Journal of Applied Polymer Science, v. 87, n. 7, p. 1059-67, Feb. 2003.
19 JOSEPH, S.; SREEKALA, M.S.; THOMAS, S. Viscoelastic properties of oil palm fibre reinforced phenol formaldehyde composites. International Journal of Plastic Technology, v 5, n 1, p. 28-35, Jan. 2002.
20 AURICH, T.; MENNIG, G. Characterization of injection moulded flax reinforced polypropylene. International Journal of Plastic Technology, v 5, n 1, p. 9-14, Jan. 2002.
21 MOHANTY, S.; VERMA, S.K; NAYAK, S.K.; TRIPATHY, S.S. Influence of fiber treatment on the performance of sisal-polypropylene composites. Journal of Applied Polymer Science, v. 94, n. 3, p. 1336-45, Nov. 2004.
22 RANA, A.K.; MITRA, B.C.; BANERJEE, A.N. Short jute fibre-reinforced polypropylene composites: dynamic mechanical study. Journal of Applied Polymer Science, v. 71, n. 4, p. 5331-9, Jan. 1999.
23 GEORGE, J.; BHAGAWAN, S.S.; THOMAS, S. Thermogravimetric and dynamic mechanical thermal analysis of pineapple fibre reinforced polyethylene composites. Journal of Thermal Analysis and Calorimetry, v. 47, n. 4, p. 1121-40, Oct. 1996.
24 MACHADO, M.A.L., BIAGIOTTI, J.; KENNY, J.M. Comparative study of the effects of different fibres on the processing and properties of ternary composites based on PP-EPDM blends. Polymer Composites, v. 23, n. 5, p. 779-89, Oct. 2002.
25 FELIX, J.M.; GATENHOLM, P. The nature of adhesion in composites of modified cellulose fibre and polypropylene. Journal of Applied Polymer Science, v. 42, n.3, p. 601-20, Feb. 1991.
2 VENKATASWAMY, K.G.; PILLAI, C.K.S.; PRASAD, V.S.; SATYANARAYANA, K.G. Effect of weathering on the mechanical properties of midribs of coconut leaves. Journal of Materials Science, v. 22, n. 9, p. 3167-73, Sept. 1987.
3 CALADO, V.; BARRETO, D.W.; D’ALMEIDA, J.R.M. The effect of chemical treatment on the structure and morphology of coir fibers. Journal of Materials Science Letters, v. 19, n. 23, p. 2151-4, Dec. 2000.
4 ROUT, J.; MISRA, M.; TRIPATHY, S.S.; NAYAK, S.K.; MOHANTY, A.K. The influence of fibre treatment on the performance of coir-polyester composites. Composites Science and Technology, v. 61, n. 9, p. 1303-10, Jul. 2001.
5 SATYANARAYANA, K.G.; GUIMARÃES, J.L.; WYPYCH, F. Studies on lignocellulosic fibers of Brazil. Part I: Source, production, morphology, properties and applications. Composites: Part A, v. 38, n. 7, p. 1694-1709, Jul. 2007.
6 SCHUH, T.G.; CAYER, U. Lignocellulosic: plastic composites. Botucatu: USP/UNESP, 1997.
7 MERCEDES-BENZ. Meio ambiente: projeto Poema: ecologia. Disponível em
8 HILL, C.A.S.; KHALIL, H.P.S.A. The effect of environmental exposure upon the mechanical properties of coir or palm fiber reinforced composites. Journal of Applied Polymer Science, v. 77, n. 6, p. 1322-30, Jun. 2000.
9 ROUT, J.; TRIPATHY, S.S.; MISHRA, M.; MOHANTY, A.K; NAYAK, S.K. The influence of fibre surface modification on the mechanical properties of coir-polyester composites. Polymer Composites. v. 22, n. 4, p 468-72, Apr. 2001.
10 MONTEIRO, S.N.; TERRONES, L.A.H.; LOPES, F.P.D.; D’ALMEIDA, J.R.M., Structural characteristics and properties of coir fiber wastes reinforced polymeric composites, In: INTERNATIONAL CONGRESS ON MATERIALS, 3., 2005, Cartagena, Colombia. Medellin: Universidad de Antioquia, 2005, p. 1-6.
11 MONTEIRO, S.N.; TERRONES, L.A.H.; LOPES, F.P.D.; D’ALMEIDA, J.R.M., Mechanical strength of polyester matrix composites reinforced with coconut fiber wastes. Revista Matéria, v. 10, n. 4, p. 571-6, Oct. 2005.
12 MONTEIRO, S.N.; TERRONES, L.A.H.; CARVALHO, E.A.; D’ALMEIDA, J.R.M. Efeito da interface fibra/matriz sobre a resistência de compósitos poliméricos reforçados com fibras de coco, Revista Matéria, v. 11, n. 4, p. 395-402, Oct. 2006.
13 MONTEIRO, S.N.; TERRONES, L.A.H.; D’ALMEIDA, J.R.M.; OLIVEIRA, L.B.. Aplicações tecnológicas para compósitos poliméricos de mantas de fibra de coco. In: CONGRESSO ANUAL DA ABM, 60., 2005, Belo Horizonte. Anais... São Paulo: ABM, 2005. p. 1540-8.
14 RAY, D.; SARKAR, B.K.; DAS, S.; RANA, A.K. Dynamic mechanical and thermo analysis of vinylester - resin – matrix composites reinforced with untreated and alkali-treated jute fibres. Composites Science and Technology, v. 62, n. 7-8, p. 911-7, Jun. 2002.
15 MOHANTY, S.; VERMA, S.K; NAYAK, S.K. Dynamic mechanical and thermal properties of MAPE treated jute/HDPE composites. Composites Science and Technology, v. 66, n. 3-4, p. 538-47, Mar. 2006.
16 KUBAT, J.; RIODAHL, M.; WELANDER, M. Characterization of interfacial interactions in high density polyethylene filled with glass spheres using dynamic mechanical analysis. Journal of Applied Polymer Science, v. 39, n. 7, p. 1527-39, Apr. 1990.
17 BIKIARIS, D.; MATZINOS, P.; PRINOS, J.; FLARIS, V.; LARENA, A.; PANAYIOTOU, C. Use of silanes and copolymers as adhesion promoters in glass fibre/polyethylene composites. Journal of Applied Polymer Science, v. 80, n. 14, p. 2877-8, Jun. 2001.
18 VAJRASTHIRA, C.; AMORNSAKCHAI, T.; LIMCHAROEN, B. Fibre-matrix interaction in aramid short fibre reinforced thermoplastic composites. Journal of Applied Polymer Science, v. 87, n. 7, p. 1059-67, Feb. 2003.
19 JOSEPH, S.; SREEKALA, M.S.; THOMAS, S. Viscoelastic properties of oil palm fibre reinforced phenol formaldehyde composites. International Journal of Plastic Technology, v 5, n 1, p. 28-35, Jan. 2002.
20 AURICH, T.; MENNIG, G. Characterization of injection moulded flax reinforced polypropylene. International Journal of Plastic Technology, v 5, n 1, p. 9-14, Jan. 2002.
21 MOHANTY, S.; VERMA, S.K; NAYAK, S.K.; TRIPATHY, S.S. Influence of fiber treatment on the performance of sisal-polypropylene composites. Journal of Applied Polymer Science, v. 94, n. 3, p. 1336-45, Nov. 2004.
22 RANA, A.K.; MITRA, B.C.; BANERJEE, A.N. Short jute fibre-reinforced polypropylene composites: dynamic mechanical study. Journal of Applied Polymer Science, v. 71, n. 4, p. 5331-9, Jan. 1999.
23 GEORGE, J.; BHAGAWAN, S.S.; THOMAS, S. Thermogravimetric and dynamic mechanical thermal analysis of pineapple fibre reinforced polyethylene composites. Journal of Thermal Analysis and Calorimetry, v. 47, n. 4, p. 1121-40, Oct. 1996.
24 MACHADO, M.A.L., BIAGIOTTI, J.; KENNY, J.M. Comparative study of the effects of different fibres on the processing and properties of ternary composites based on PP-EPDM blends. Polymer Composites, v. 23, n. 5, p. 779-89, Oct. 2002.
25 FELIX, J.M.; GATENHOLM, P. The nature of adhesion in composites of modified cellulose fibre and polypropylene. Journal of Applied Polymer Science, v. 42, n.3, p. 601-20, Feb. 1991.
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