Study of cure process of thick solid rubber

Abstract

Experimental and numerical studies have been performed for the cure process of solid rubber. Styrene-butadiene rubber (SBR) packed in a cylindrical mold of inner diameter 74.6 mm, was heated by one-dimensional, transient heat conduction from the mold. Radial temperature profile and also radial distributions of the degree of cure were measured after the prescribed heating time was reached. Two methods for the mold temperature control were adopted. One is that the heating is continued at a constant temperature until the uniform temperature profile across the rubber was observed. The other is that the heating was cut off before the uniform profile was formed in order to study the effects of residual heat on the cure process. Numerical prediction was performed for the distributions of the temperature and degree of cure. Heat conduction equation for one-dimensional, transient heat transfer is coupled to the cure kinetics of the SBR. Heat generation term, expressed as a function of cure rate and the total heat generation due to cure reaction, is introduced to account for the effect of heat liberated during the process. Results of the prediction showed a good agreement of the measured profiles of the temperature and the degree of cure.