Speciality polymer blends of polyurethane elastomers and chlorinated polyethylene rubber (peroxide cure)

Two elastomers having polar reactive functional groups may react with each other upon heating. Considering this view, blends of polyurethane (AU) and chlorinated polyethylene (CPE) elastomer have been prepared where better pe rformance properties can be obtained through interchain crosslinking reacti on. The entire study was carried out using dicumyl peroxide (DCP) as a curi ng agent where both the phases were vulcanized to form new materials. The s tate of cure gradually increased with the addition of CPE. Hardness, modulu s and tensile strength were also increased with increase of CPE content. Th e elongation at break decreased with higher amount of CPE. After ageing, ha rdness increased but the modulus and tensile strength decreased. There was drastic change in elongation at break on ageing. IR spectra suggested that interchain crosslinking occurred between AU and CPE elastomers. High temper ature DSC studies also revealed the improvement of thermal stability with t he addition of CPE. SEM. study also suggested interphase crosslinking. (C) 2000 Society of Chemical Industry.