STUDY ON THE THERMAL-DEGRADATION OF EPOXIDIZED NATURAL-RUBBER

The thermal degradation and thermooxidative degradation of epoxidized natural rubber (ENR) were studied by thermogravimetry (TG). In the the rmal 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 mea n 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 v alue 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 approxi mately 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 the rmal degradation of ENR and the difference of the mechanisms of the tw o reaction systems is obvious. (C) 1998 John Wiley & Sons, Inc.