COMPARATIVE STUDY BETWEEN METALLOCENE POLYOLEFIN BLENDS MODIFIED BY BETA-IRRADIATION AND A SILANE CROSSLINKING PROCESS

摘要

Three binary groups of metallocene blends of ethylene-1-Octene copolymer (80 and 50 weight %) with two metallocene ethylene-1-Octene copolymers of different crystalline density and a metallocene EPDM were made in a co-rotating twin-screw extruder.The first group corresponds to blends without chemical modification.In the second group the dispersed phase was grafted with vinyl-triethoxy silane by means of a reactive extrusion process (SIOPLAS).The blends of the third group were crosslinked with Beta-Radiation at 200 KGy as final dose.The gel content of the crosslinked blends showed higher values for those blends crosslinked by Beta-Irradiation than SIOPLAS process.DSC using a heat treatment known as Successive Self-Nucleation/Annealing (SSA) and DMA techniques were used to analyze the effect of the comonomer content on the crystalline morphology of the crosslinked materials.Important changes in crystalline morphology of the blends due to the crosslinking process were observed.