Effect of Zinc Dimethacrylate on Mechanical Properties of Dynamically Vulcanized Polypropylene(PP) and Nitrile rubber(NBR) Blends

Thermoplastic elastomer was prepared from dynamical vulcanization of isotactic polypropylene(iPP)/nitrile rubber blend (NBR/iPP=70/30 wt/wt) in an internal mixer using dicumyl peroxide (DCP) as a curing agent and zinc dimethacrylate (ZDMA) as a coagent. There was a great improvement in tensile and tear strength, elongation-at-break and lower tension set when ZDMA was incorporated into the blend, which is supposed to be due to the increase in crosslink density of the rubber phase and the reduction in size of the rubber particles. It was revealed that the dynamically vulcanized blend exhibited good reprocessibility, indicating its thermoplastic nature.