间规1,2-聚丁二烯的非等温结晶动力学

KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION OF SYNDIOTACTIC 1,2-POLYBUTADIENE

结合Avrami和Ozawa方程,构筑了一个新的聚合物非等温结晶动力学方程.以铁催化体系间规1,2聚丁二烯(st- 1,2PB)为例,将新方法与其他常用的Jeziony和Ozawa方法的处理结果进行比较.发现由Jeziony方法分析得到的表观Avrami指数不能直接用于预测st -1,2PB的非等温结晶机理.由Ozawa方法分析实验数据,得到的线性关系很差,因此也很难得到可靠的动力学参数.而采用新方法可得到一系列线性关系较好的直线.根据新参数a与表观Avrami指数n和Ozawa指数m的关系,st -1,2PB的结晶机理可以预测且与等温方法获得的结果有可比性.这种新方法已应用于聚醚酮、聚酰胺、聚烯烃、烷基取代聚噻吩、聚(β-羟基丁酸酯)及其共混物等多种聚合物体系中.

By combining the Avrami and Ozawa equations, a new kinetic equation for describing the non-isothermal crystallization process of polymers was obtained. The comparison among the new method and other commonly used methods such as Jeziony and Ozawa methods was conducted with the syndiotactic I 2-polybutadiene ( st -1, 2 PB) as an example. The results suggested that the apparent Avrami exponent obtained by the Jeziony method can not predict the mechanism of non-isothermal crystallization of st-1, 2 PB. The Ozawa method is also limited in obtaining the reliable kinetic parameters because of the substantial curvatures in the Ozawa plots. However, the analysis based on the new method gives a series of straight lines. According to the relationship among the new parameter a, the apparent Avrami exponent n, and the Ozawa exponent m in the new method,the mechanism of crystallization of st-1,2 PB can be predicated and the result is comparable with that obtained by the isothermal crystallization. The new method is an effective method for dealing with the kinetics of non-isothermal crystallization of many polymeric systems, such as PEAKs, polyamides, polyolefins, poly ( 3-alkylthiophenes) poly ( P-hydroxybutyrate) and some blending systems.