On the heat shrinkability and interchain crosslinking of blends consistingof grafted ethylene-propylene polymer and polyurethane elastomer

Blends prepared by melt mixing of thermoplastic materials/elastomers have g ained considerable attention in recent years from the viewpoint of heat shr inkability. The present study deals with the measurement of heat shrinkabil ity of the blends of grafted ethylene-propylene polymer and polyurethane el astomer. The used grafting materials are acrylic acid, vinyltriacetoxysilan e, and glycidyl acrylate. Interchain crosslinking between grafted ethylene- propylene polymer and polyurethane elastomer improves the heat shrinkabilit y. The high temperature performance of the sample is dependent on interchai n crosslinking. From torque rheometry it was observed that the maximum amou nt of interchain crosslinking occurred in the sample containing glycidyl ac rylate as grafting material. The probable interaction between rubber and pl astic phase was confirmed by IR spectroscopy.