Biofiber‐reinforced polypropylene composites

Abstract

Biofibers. natural lignocellulosics, have an outstanding potential a s a reinforcement in thermoplastics. This study deals with the preparation of lignocellulosic composites by reactive extrusion processing in which good interfacial adhesion is generated by a combination of fiber modification and matrix modification methods. PP matrix was modified by reacting with maleic anhydride and subsequently bonded to the surface of the modified lignocellulosic component, in-situ. The fiber surface was modified by reacting it with a silane in a simple and quick aqueous reaction system, similar to that employed for glass fibers. The modified fibers are then extruded with the modified polymer matrix to form the compatibilized composite. The various reactions between the lignocellulosic fiber/filler and modified polymer chains, is expected to improve the interfacial adhesion significantly a s opposed to simple mixing of the two components, since new covalent bonds between the fiber surface and matrix are created in the former case. These composite blends were then injection molded for mechanical characterization. Typical mechanical tests on strength, toughness and Izod impact energy were performed and the results are reported. These findings are discussed in view of the improved adhesion resulting from reactions and enhanced polar interactions at phase boundaries.

Compósitos termoplásticos com madeira

“…Considerações sobre processo, compatibilização e propriedades têm sido abordadas por inúmeros autores [10][11][12][13][14][15][16][17] . Esse amplo interesse baseia-se no fato de que a incorporação de fibras naturais em termoplásticos poliolefínicos apolares, o caráter polar da celulose requer a compatibilização do sistema através da incorporação dos chamados agentes de acoplamento ou de adesão interfacial.…”

Compósitos de HDPE com resíduos de fibras têxteis. Parte I: caracterização mecânica

“…A Tabela 3 mostra os valores dos resultados dos ensaios mecânicos de tração, flexão e impacto para composições utilizando teor de resíduo de fibra têxtil de 0 a 40% em peso, utilizando 5 …”

“…Entretanto, existe a tendência de maior utilização de fibras sintéticas, gerando economia de escala para a produção, e possibilitando a modernização e aumento da produtividade no processo de f iação [5] . O Brasil é um importante produtor mundial de artigos têxteis, ocupando a sétima posição na produção de fios e tecidos planos e a terceira na produção de tecidos de malha [6] .…”

Vinyl Acetate Modified Scots Pine Reinforced HDPE Composites: Influence of Various Levels of Modification on Mechanical and Thermal Properties

“…These include chemical or physical modifications of the fiber such as reaction with acid compounds (Karnani et al 1997;Zafeiropoulos et al 2002), organosilane (Kokta et al 1989;Karnani et al 1997), and alkali treatments (George et al 2001). …”