Effects of interfacial structure on the mechanical properties of epoxy resin and poly(vinyl chloride) modified with crosslinked poly(methyl methacrylate) particles

摘要

The effect of interfacial adhesion on the mechanical properties of an incompatible polymer blend was investigated. For this purpose, the preparation of uncrosslinked and crosslinked poly (methyl methacrylate) particles having mean sizes of about 0.8250L蘭 was completed by a seeded emulsion polymerization, and amount of crosslinked points in the particles were varied. The obtained emulsion particles were powdered by a freeze dry method and dispersed into poly(vinyl chloride) matrix, as typical ductile polymer, by a melt blending. The mutual diffusion of the polymer molecules at particle/matrix interfacial regions was restricted by the crosslinked points, because of poly(methyl methacrylate) has a good compatibility with poly(vinyl chloride). And then, the good interfacial adhesion was obtained at the optimum amount of crosslinked points in the particles. The yield stress and the fracture toughness never decreased, when the interfacial adhesion is sufficient. Subsequently, the particles were dispersed into epoxy resin, as typical brittle polymer, which has also a good compatibility with poly(methyl methacrylate). However, the good adhesion was never obtained in the epoxy system, therefore, the fracture strength and the fracture toughness decreased with the incorporation of particles.