Influence of Different Curing Systems on the Physico-Mechanical and Rheological Properties of CSM Rubber

Abstract

Curing systems play a vital role in designing rubber compounds for various industrial applications. Keeping this in view, a comparative study of the effects of four different curing systems such as sulfur, dicumyl peroxide (DCP), metal oxide (PbO) and epoxy resin on the curing characteristics, physico-mechanical, and rheological properties of chlorosulfonated polyethylene rubber (CSM) has been carried out. The highest values of maximum rheometric torque and scorch safety were observed in the peroxide-cured system, whereas sulfur-cured CSM rubber compounds possessed superior mechanical and rheological properties compared to those of the other cured systems. It is interesting to note that all curing systems exhibited increases in tensile strength, hardness, tear strength and crosslink density after aging. This may be due to post vulcanization. Unlike uncured CSM compound, in cured CSM compound the loss tangent increased with frequency, which may be due to the insufficient time available for molecular relaxation. Probable crosslinked structures for different curing systems have been proposed based on the observations of attenuated total reflectance Fourier transform infrared spectroscopy.