Kinetic Study of Oxidative Scission in Natural Rubber by Wallace Plasticity Measurements

Abstract

Abstract The kinetics of thermal oxidative degradation of natural rubber (NR) have been studied by Wallace plasticity measurements. On the basis of the Kotliar's model of random chain scission, an expression was derived to interpret the kinetic data collected over a range of temperatures from 80 to 160°C. It has been shown that the kinetic parameter resulting from the present analysis, indeed refers to a diffusion-controlled reaction with an overall activation energy estimated to be 135 ± 6 kJ · mol−1. In addition, the implications of plasticity retention index, which measures the oxidizability of NR, are discussed.