Heat Shrinkable Polymer Blends Based on Grafted Low-Density Polyethylene and Carboxylated Nitrile Rubber

Abstract

Heat shrinkability of a polymer, which depends on the elastic memory, was introduced into the system in the form of an elastomeric phase. The present study deals with the measurement of heat shrinkability of the blend of grafted low-density polyethylene and carboxylated nitrile rubber. The grafting materials used in this study were acrylamide, vinyl triacetoxy silane, and maleic anhydride. Coupling agents used were 4,4′-diamino diphenyl methane and 4,4′-diamino diphenyl sulphone. It was found from torque rheometry and swelling studies that the degree of interchain crosslinking was greatest when 4,4′-diamino diphenyl methane was used as a coupling agent in the maleic anhydride grafted low-density polyethylene, while it was lowest when 4,4′-diamino diphenyl sulphone was used as a coupling agent. Shrinkability of the high temperature stretched sample was more than that of room temperature stretched sample. It was found from XRD that the crystallinity of the stretched sample was more than that of original sample. It was observed from the high temperature DSC that the interchain crosslinking was responsible for the enhancement of the thermal stability of the sample. Interchain crosslinking between grafted polyethylene and elastomer improves the shrinkability. Probable interactions between the rubber and plastic phase were confirmed by IR spectroscopy.