Influence of interfacial adhesion on the mechanical properties and fracture behaviour of short sisal fibre reinforced polymer composites

Abstract

The mechanical properties of sisal fibre composites (randomly oriented) of several thermoset resin matrices, [polyester, epoxy, phenol-formaldehyde] and a thermoplastic matrix [low density polyethylene (LDPE)] were evaluated with respect to fibre length and fibre loading. All the composites showed a general trend of increase in properties with fibre loading. However, the optimum length of the fibre required to obtain an increase in properties varied with the type of matrix. Among polyester, epoxy and phenol-formaldehyde composites of sisal fibre, a phenolic type resin performed as a better matrix than epoxy and polyester resins with respect to tensile and flexural properties due to the high interfacial bonding in phenolic composites. However, as compared to thermoset resin composites, sisal fibre-LDPE composites showed a better reinforcing effect due to the high matrix ductility and high strength/modulus ratio of sisal as compared to that of LDPE matrix.