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 performance properties can be obtained through interchain crosslinking reaction. The entire study was carried out using dicumyl peroxide (DCP) as a curing agent where both the phases were vulcanized to form new materials. The state of cure gradually increased with the addition of CPE. Hardness, modulus and tensile strength were also increased with increase of CPE content. The elongation at break decreased with higher amount of CPE. After ageing, hardness 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 temperature DSC studies also revealed the improvement of thermal stability with the addition of CPE. SEM study also suggested interphase crosslinking. © 2000 Society of Chemical Industry