Kinetic study on cross‐linking and blowing behavior of EVA/EPDM/CPE high elasticity material

Blend of ethylene‐vinyl acetate copolymer (EVA), ethylene‐propylene‐diene terpolymer rubber (EPDM), and chlorinated polyethylene (CPE) filled with talc was cross‐linked with dicumyl peroxide and blown simultaneously with azodicarbonamide for preparation of high elasticity material by injecting, cross‐linking, and blowing process. It had excellent mechanical properties and elasticity. It was found that mechanical properties were a function of cross‐linking and blowing temperature and time and formula. A good cross‐linking and blowing temperature was in the range of 440–450 K and the optimum temperature and time were 448 K and 360 s, respectively. Kinetics of both cross‐linking and blowing reactions were investigated by closed nonrotor torque rheometer. The results showed that both cross‐linking and blowing reactions were first order. The activation energy of the cross‐linking reaction was higher than that of the blowing reaction. With increasing of EDPM content, the activation energy of the cross‐linking reaction reduced whereas it increased for the blowing reaction. The gas cell morphology was characterized by scanning electron microscopy (SEM). The results of SEM and mechanical property analyses showed that the morphology and mechanical properties were improved by incorporating CPE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007