氯乙烯-丙烯酸丁酯共聚物热解机理的研究

Studies on the thermal degradation process of the copolymer of vinyl chloride and butyl acrylat

用 TG- DSC法研究氯乙烯 (VC) -丙烯酸丁酯 (BA)共聚物的热降解机理 .考察了升温速率 (β)、气氛对热降解的影响 .实验表明 :随 β值增大 ,VC- BA共聚物的热降解出现最大降解速率时的温度 (Tp)和降解 1 0时的温度 (T0 .1 )都升高 ,但对最终降解率影响不大 ;在气氛一定时 ,Tp时的降解率是一个常数 .在氮气气氛中的 Tp 比空气气氛中的 Tp高 ,且 VC- BA共聚物的热降解反应是吸热反应 ,它的降解分两步进行 ,第一步是脱除支基 ,第二步是主链断裂 ;在空气气氛中 ,VC- BA的热降解是放热反应 ,降解分三步进行 (第三步有待完成 ) ,第一步也是脱除支基 。

It uses the TG-DSC method to study the thermal degradation process of the copolymer of vinyl chloride and butyl acrylat.The effects of heating rates and atmospheres on the thermal degradation have been examined. When the heating rates rise, the temperatures of the degradation peak(T p) and 10% (T 0.1 ) go up, but the effect on t he final ratio of the degradation is not serious; When the atmosphere is fixed,the degradation ratio on T p is a constant.When the T p in nitr ogen is higher than the T p in air,the degradation reaction in N 2 is endo thermi c,but in air is exothermic. The degradation reaction in N 2 divides into two steps: the first eliminates the branch bases;in the second, the main chain breaks. In the air the reaction divides into three steps (The third is to be finished).