Mechanical properties and dimensional stability of jute/VER-isocyanate hybrid matrix composites

Abstract

Some composites of alkali treated jute fibers and vinylester-isocyanate/urethane hybrid resin were fabricated. The mechanical, thermo-mechanical, fractographic and aging behavior of these composites were studied and compared with the parent vinylester resin (VER) matrix composites. Using hybrid resin matrix, the impact strength of jute composites was increased by ∼20% over the VER matrix composites. It was, however, accompanied by the marginal improvement in their tensile and flexural properties. Dynamic mechanical analysis showed increased storage modulus and broadened tan δ peak when VER-isocyanate hybrid resin was used as a matrix material compared with the parent VER matrix in jute composites showing its superior stiffness and flexibility. In humid environment, a decrease in the weight gain and swelling thickness was observed for VER-isocyanate hybrid matrix jute composites after 60 days exposure when compared with the parent VER matrix composites. Under accelerated water aging, the drop of 12–24% in the tensile strength was noticed for VER-isocyanate hybrid matrix jute composites as compared to ∼29% for VER matrix composites. The changes in the mechanical response of all composites can be well co-related with their fractographic evidences existed onto the tensile fracture surfaces in both dry and wet conditions.