Writer：Wei Wu
Publication: China Rubber Industry, 1996, 6: 323-327
Abstract: The morphologic characteristics and toughened effect of three EPDMs in dynamically vulcanized PP/ EPDM blends w ere investigated by SEM and the ethylene contents in the said EPDMs were 53%, 45% and 75% by w eight respectively. The results showed that the EPDM with the ethylene content between 45% ~ 55% by w eight gave lower structure regularity, higher melt ing viscosity and poor compatibility with PP, the dynamic vulcanization resulted in smaller dispersive EPDM granules, more uniform granule size and distribution, and the increase of shearing strength in blending was benefit ial to the toughening effect of this EPDM; and the EPDM w ith the ethylene content up to 75% by w eight gave partial crystallinity due to the format ion of homopolymerized ethylene in EPDM, lower melting viscosity and better compatibility w ith PP, the dynamic vulcanization resulted in greater dispersive EPDM granules and a subnetwork structure, the network density and continuity w ere increased by promoting the chemical crosslinking reaction and thus the toughened effect w as increased, in cont rast ,the toughened effect was decreased by increasing the shearing streng th in blending.
