Vulcanization of ethylene-propylene–terpolymer-based rubber mixtures by radiation processing

Abstract

Elastomers are materials used in a large range of industrial and household applications. A common physical-chemical treatment is curing (crosslinking), imparting the rubber mechanical and thermal stability. Elastomers show low thermal conductivity values, and therefore, require complex and high-cost heating methods; thus, the ionizing (accelerated electrons) method shows high interest for the grafting and crosslinking processes. In addition to the lack of environmental impact, reliability, flexibility, and low costs render the radiation technologies especially attractive. The article presents the results concerning trimethylolpropane-trimethacrylate coagent concentration effect, on the mechanical properties of the ethylene-propylene–terpolymer (EPDM) rubber vulcanized by electron beam (EB). Mechanical properties of EB irradiated samples were compared with the dibenzoyl peroxide cured samples. Dependence of mechanical properties on irradiation dose was determined from a dose range of 0 kGy to 200 kGy. Dibenzoyl peroxide vulcanization at 160°C was carried out on the EPDM samples as well. Two types of blends have been analyzed: fillers and nonfillers. The results showed an increase in mechanical properties as a function of increasing polyfunctional monomer level. Also, based on the comparison between EB and dibenzoyl peroxide vulcanization efficiency, the results show that EB irradiation gave the best results. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013