不同二氧化钛含量的PET非等温结晶动力学研究

用DSC、非等温结晶动力学方法研究了PET切片中不同二氧化钛含量对其结晶性能的影响。结果表明:适量的二氧化钛在聚合过程中起成核剂作用,随着切片中二氧化钛含量的增加,聚合物结晶速度加快,质量分数超过0.33％时,对熔体成核结晶有阻滞作用。结晶能力在冷却速率和二氧化钛含量变化时基本不变,说明二氧化钛的加入对聚合物的结晶能力影响不大。不同二氧化钛含量不同冷却速率的Avrami指数平均值都在4.0以上,可以认为结晶以均相成核为主,三维生长。

Study on non-isothermal crystallization kinetics of PET containing different amounts of titanium dioxide

The effect of titanium dioxide content on the crystallization behavior of PET was studied by DSC and non-isothermal crystallization kinetic methods. The results showed that titanium dioxide of rational amount acted as a nucleating agent during polymerization. The crystallization rate was increased with the amount of titanium dioxide in PET chips. Titanium dioxide higher than 0. 33% inhibited the nucleation. The crystallization capacity of PET remained unchanged basicly while changing cooling rate and titanium dioxide content, which indicated that the incorporation of titanium dioxide had a slight effect on the crystallization capacity. The average of Avrami index was above 4. 0 at different titanium dioxide content and crystallization rate. The crystals exhibited homogeneous nucleation and three-dimensional growth.