目的 PET 与 PCTG 和 SiO2 共混是提高 PET 综合性能的一种途径，研究共混材料的热性能的变化规律来为共混材料的共混工艺提供理论基础。方法 测定 PET 与 PCTG 及不同粒径 SiO2 的共混材料的升温和降温 DSC 分析曲线， 研究 PCTG 和 SiO2 的粒径和用量对 PET/PCTG/SiO2 共混材料的冷、热结晶性能的影响。 结果 PET 与 PCTG 和 SiO2 共混， PCTG 和 SiO2 的加入会降低 PET 的冷结晶温度，提高热结晶温度， SiO2 用量越大，冷结晶温度降低和热结晶温度提高的幅度越大。 结论 PCTG 和 SiO2 对冷、热结晶温度的协同影响较大， SiO2 的粒度对 PET/PCTG/SiO2 冷结晶温度影响较小，对热结晶温度影响较大， SiO2 的粒度越小，热结晶温度越高。

Blend of polyethylene terephthalate (PET) with SiO2 and poly terephthalate (PCTG) is a way for improving comprehensive characteristics of PET. Investigation of the variation law of the thermal behavior of the blended material may provide theoretical basis for the blending technology of PET/ PCTG /SiO2. By determination of the temperature increase and decrease differential scanning calorimetry (DSC) curves of the blends containing PET, PCTG and SiO2 with different particle sizes, the effects of the particle size and dosage of SiO2 and PCTG on the cold and hot crystallinity of PET/ PCTG /SiO2 blend were studied. In the PET/ PCTG /SiO2 blend, the addition of PCTG and SiO2 would reduce the cold crystallization temperature and increase the hot crystallization temperature. The higher the SiO2 dosage, the lower the cold crystallization temperature and the higher the hot crystallization temperature of PET/PCTG/SiO2 blends. PCTG and SiO2 had relatively large synergic effect on the cold and hot crystallization temperature, whereas the grain size of SiO2 had relatively small effect on the cold crystallization temperature and relatively large effect on the hot crystallization temperature. The smaller the grain size of SiO2, the higher the hot crystallization temperature.