Effect of cure systems on shrinkability of polyolefin–EPDM blends

Effects of cure systems on shrinkability of polyolefin and EPDM blends have been studied as a function of cure time and amount of elastomers added. During measurement one of the parameters is kept constant while the other varies. The shrinkability of the blends increases with the increase in cure time when elastomer content is fixed. Similarly, at constant cure time higher loading of elastomer increases the shrinkability of the blends. Samples stretched under high temperature show higher shrinkability than those stretched under room temperature. Dicumylperoxide (DCP) is a more effective curing agent for making a particular set of blends more shrinkable than the sulfur. The changing morphological pattern with DCP-cured shrunk samples from those of sulfur cured samples is corroborated by the SEM studies where the elastomer phase appears to be globular in nature. The crystallinity of the blend depends on the dose and type of the elastomer used in polyolefin. The curing efficiency of the elastomerphase depends on the polyolefin used as blend partner. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 597–603, 1998