PEN非等温冷结晶动力学的研究

摘要

采用差示扫描量热(DSC)法对聚萘二甲酸乙二醇酯(PEN)的非等温冷结晶动力学进行研究；通过改变升温速率,讨论了PEN冷结晶起始温度与峰顶温度之间存在差值的原因；对比了两种不同的冷结晶起始点的确定方法对冷结晶动力学常数的影响.结果表明:以DSC曲线偏离基线作为PEN冷结晶的起始点,得到的表观Avrami指数很大；用基线延长线与DSC曲线的切线的交点作为冷结晶的起始点和结束点,得到的表观Avrami指数为2.55,且不随升温速率的变化而变化,与等温熔融热结晶方法得到的结果接近,具有相似的结晶生长方式.%The nonisothermal cold crystallization kinetics of poly(ethylene-2,6-naphthalene dicarboxylate) (PEN) was studied by differential scanning calorimetry (DSC). The reasons for the difference between the onset and peak temperatures of PEN cold crystallization was discussed at different heating rate. The effects of two onset temperature determination methods on kinetic parameters of cold crystallization were compared. The results showed that if the deviation of DSC curve from the baseline is assumed as the onset temperature of cold crystallization, the obtained apparent Avrami index was quite high; if the intersection of the DSC baseline and tangent is assumed as the onset temperature of cold crystallization, the obtained apparent Avrami index was 2.55, independent from the heating rate; the value was close to that obtained by isothermal melt thermal crystallization, and these two methods contributed similar crystal growth.