Study on the thermal degradation of epoxidized natural rubber

摘要

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 T-0 = 1.20B + 348, the temperature of maximum weight loss rate T-p = 1.07B + 392, and the final temperature of weight loss T-f = 0.77B + 445. The C-p, which corresponds to the degradation rate at temperature T,, T,= 0.77B + 445. The C increases along with the heating rate B and its mean value is 43%, but C-f, 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, T-0 = 1.84B + 246, T-p = 0.30B + 378, and T-f = 2.27B + 584. The value of C-p increases along with the heating rate B and its mean value is 36%, but C-f 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. (C) 1998 John Wiley & Sons, Inc. [References: 11]