CURE KINETICS OF BUTYL RUBBER CURED BY PHENOL FORMALDEHYDE RESIN

Abstract

The characterization of rubber compounds is a necessary step for simulating rubber products manufacturing processes. We study experimentally and model computationally compounds of Butyl rubber cured by Phenol Formaldehyde Resin, a rubber used for making curing bladders, a key component in the tire industry. Several compounds, differing in the proportions of resin, Zinc Oxide, Polychloroprene (CR) and Stearic Acid, are experimentally tested during the curing process using a moving die rheometer. The experimental results are used to ï¬nd the parameters of two well established kinetic models, namely the Nth order and the Kamal-Sourour models. Both models include an ordinary differential equation for the degree of cure and an algebraic relation between torque and temperature. The ï¬tting of the model parameters is rearranged as an optimization problem, and solved using the Levenberg-Marquadt algorithm. The results show that both models are able to represent the behavior of these compounds, although the more involved Kamal-Sourour model performs better for early times, as expected. The parameter values found are useful for numerical simulations of curing bladder manufacturing processes, and as a reference for further studies of similar compounds.