Analysis of the fracture behavior of polypropylene: sawdust composites

Abstract

Natural fiber reinforced composite is an emerging area in Polymer science. The use of lignocellulosic materials in thermoplastic composites may contribute to reduce the waste of vegetal biomass. The natural fibers are biodegradable, low cost materials having density and specific properties comparable to those of conventional fiber composites. In this work composites of polypropylene (PP) plus maleated polypropylene (MAPP) filled with sawdust were prepared under fixed processing conditions (mixing temperature, mixing time and rate of rotation). The composites were fractured by tension and the fracture mechanisms were characterized by scanning electron microscopy. The SEM studies of the fractured surfaces of the composites indicate that the failure is due to fiber pull-out accompanied by tearing of the matrix; the pull-out increases with MAPP content

Gamma radiation effect on sisal / polyurethane composites without coupling agents

“…In both cases, the fracture aspect was the same observed for the dispersed fiber composite, with embrittlement of micro fibrils after irradiation and no presence of interfacial gaps between the fibers and the polymer matrix. The absence of fiber-matrix interfacial gaps was reported by other authors [32,33] only for fibers that were treated with coupling agents, witchy suggests that the chemical affinity between the materials investigated in this work is suitable even without the use of coupling agents.…”

Thermal Behavior of Isotactic Poly(propylene)/Maleated Poly(propylene) Blends

“…[15][16][17][18][19] Studies on the miscibility of isotactic poly(propylene) (IPP) with PP-g-MA [15][16][17] have established that, depending on their molecular weight and the MA content in PP-g-MA, such polymers can either co-crystallize or phase-separate. In the case of high molecular weight and low MA content, the pair tends to co-crystallize, otherwise, phase separation occurs, which would influence the mechanical properties of IPP/PP-g-MA-based materials.…”

Desenvolvimento de PVC reforçado com resíduos de Pinus para substituir madeira convencional em diversas aplicações

“…A experiência brasileira com polímeros reforçados com reforços lignocelulósicos é limitada, conforme evidencia pesquisa bibliográfica preliminar [7] . Pode-se afirmar que este tema é desenvolvido no Brasil somente em alguns poucos centros de pesquisa, dentre as quais pode-se citar a Embrapa -São Carlos [9][10][11][12] , o Departamento de Engenharia de Materiais da Universidade Federal de São Carlos [13][14][15][16][17] , o Departamento de Engenharia de Materiais da Universidade Federal de Campina Grande [18,19] , o Instituto Militar de Engenharia [20] , o Instituto de Macromoléculas Prof a Eloísa Mano da Universidade Federal do Rio de Janeiro [21] , a Universidade São Francisco [22] e a Faculdade de Engenharia Industrial [23,24] .…”