过氧化物预硫化与硫黄硫化制备的医用天然胶乳制品热氧稳定性的差异

Differences between Thermal-Oxidative Stability of Medical Natural Rubber Latex Products Prepared by Peroxide Pre-vulcanization and Sulfur vulcanization

用TG DTG方法研究动态空气状态下过氧化物预硫化天然胶乳 (PPVL)制品试样和硫黄硫化天然胶乳制品试样的热氧降解。结果表明 ,PPVL试样和硫黄硫化体系试样的热氧降解反应为二步反应 ,前者的热氧降解起始温度T0 ,DTG主降解峰温度Tp,终止温度Tf 均明显低于后者 ,反应活化能也明显低于后者 ;在较低温度下 ,两者均出现增重过程 ,前者比后者较明显 ,是后者的 4 7倍 ;DTA曲线显示 ,前者出现的放热效应初始温度比后者提前。

Under dynamic air, the thermal-oxidative degradation of peroxide pre-vulcanized (PPVL) natural rubber latex products and sulfur-vulcanized natural rubber latex products were studied by use of TG-DTG. The results showed that the thermal-oxidative degradation of both PPVL samples and sulfur-vulcanized samples was two-step reaction. As to the former, the initial temperature of thermal-oxidative degradation (T 0),the temperature of main degradation peak (T P1),the initial temperature (T f) as well as the activation energy were obviously lower than those of the latter. Both of them would occur weight gain at lower temperature, while the former was more significant, i.e. it was 4.7 times greater than the latter. As seen by DTA curves, the initial temperature of exothermic effect occurred in the former was earlier than that of the latter.