有机硅磷酸酯对PBT/PET酯交换反应的影响

采用两次循环扫描方法研究了有机硅磷酸酯对聚对苯二甲酸丁二醇酯/聚对苯二甲酸乙二醇酯（PBT/PET）酯交换反应的影响，测定了PBT/PET合金的结晶性能、热变形温度、力学性能和相对黏度，并与常规的抑制剂亚磷酸三苯酯进行了比较。结果发现：加入有机硅磷酸酯后PBT/PET合金的结晶温度提高了4.5 ℃，相对黏度提高了0.1 dL/g，热变形温度提高了7.0 ℃。而加入亚磷酸三苯酯后PBT/PET合金的结晶温度降低了1.5 ℃。说明有机硅磷酸酯可有效控制PBT/PET合金中端羟基的含量，从而可有效抑制PBT和PET之间的酯交换反应。亚磷酸三苯酯和有机硅磷酸酯的加入对PBT/PET体系的力学性能影响不大。

Effect of Silicone Phosphate on Transesterification Reaction in PBT/PET Blend

The effect of silicone phosphate on the transesterification reaction in the PBT/PET blend was studied using differential scanning calorimetry by observing the crystallization and melting behavior during two cycles of heating and cooling scannings. Upon addition of silicone phosphate, the crystallization temperature of PBT/PET blend increased by 4.5℃, the relative viscosity increased by 0.1 dL/g, and the heat deflection temperature increased by 7.0℃, based on the neat system. In contrast, the counterpart containing TPPi showed a decrease of 1.5C in crystallization temperature. Silicone phosphate was more effective than TPPi in decreasing the content of end hydroxyl groups and thus more effective in depressing the transesterification between PBT and PET. The introduction of inhibitors did not influence much the mechanical properties of the blends.