| Abstract: | The thermal degradation and thermooxidative degradation of epoxidized natural rubber (ENR) were studied by thermogravimetry (TG). In the thermal degradation of ENR, the initial temperature of weight loss T0 = 1.20B + 348, the temperature of maximum weight loss rate Tp = 1.07B + 392, and the final temperature of weight loss Tf = 0.77B + 445. The Cp, which corresponds to the degradation rate at temperature Tp, increases along with the heating rate B and its mean value is 43%, but Cf, which corresponds to the degradation rate at temperature Tf, is not affected by the heating rate, and its average value is close to 100%. As in the thermooxidative degradation, T0 = 1.84B + 246, Tp = 0.30B + 378, and Tf = 2.27B + 584. The value of Cp increases along with the heating rate B and its mean value is 36%, but Cf is not affected by the heating rate and the average value approximately equals 100%. The thermal degradation in nitrogen could be a one-step reaction, whereas the thermooxidative degradation has a multiple-step reaction. The reactive environment has a great effect on the thermal degradation of ENR and the difference of the mechanisms of the two reaction systems is obvious. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2207–2211, 1998 |
