丁腈橡胶热降解的影响因素分析

Factors Influencing Thermal Degradation of NBR

采用热重分析法对丁腈橡胶(NBR)热降解的影响因素进行分析。结果表明:交联可加快NBR热降解,降低热降解温度;生胶门尼粘度对NBR热降解无影响;随着丙烯腈质量分数的增大,NBR最大降解速率温度降低,最大质量损失速率减小;升温速率较小时,丙烯腈质量分数对最大质量损失速率和最大降解速率温度的影响较大;升温速率增大,最大降解速率温度升高,丙烯腈质量分数越大,最大降解速率温度受升温速率的影响越大,升温速率对最大质量损失速率的影响恰好相反;与氮气气氛相比,空气气氛下炭黑/NBR硫化胶的降解温度升高,降解速率减小。

The factors influencing the thermal degradation of NBR were analyzed by thermogravi- metric analysis. The results showed that crosslinking could accelerate NBR thermal degradation and reduce the thermal degradation temperature. Mooney viscosity of raw rubber had no significant effect on NBR thermal degradation. With acrylonitrile content increased, the maximum weight loss tempera- ture and the maximum weight loss rate decreased. The influence of acrylonitrile content at the maxi- mum weight loss rate and maximum weight loss temperature was great at low heating rate conditions. With heating rate increasing, the maximum weight loss temperature increased, and the higher the acry- lonitrile content was, the greater the influence of heating rate on the maximum weight loss temperature was. Interestingly,the influence of heating rate on the maximum weight loss rate was just opposite. Compared with N2 atmosphere, the degradation temperature of carbon black/NBR vulcanizate was higher in air atmosphere, and the degradation rate was lower.