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聚对苯二甲酸乙二酯(PET)薄膜经固相缩聚反应后,用凝胶色谱法测定产物的分子量、分子量分布和环状齐聚物含量.结果发现,PET在180—240℃之间的固相缩聚反应除了在220℃以上略有偏离外,基本遵循二级动力学规律。反应活化能为24.29kcal/mol,与熔融聚合反应活化能接近;反应速度常数比相应温度下后者的速度常数(外推值)大;分子量分布略有加宽;环状齐聚物含量随反应温度提高和反应时间的延长而逐步减少.
The molecular weight, molecular weight distribution and cyclic oligomer content of polyethylene terephthalate (PET) film were determined by gel chromatography after solid-state polycondensation reaction. The results showed that PET was between 180-240 ℃ Solid phase polycondensation reaction in addition to a slight deviation above 220 ℃, the basic follow the second-order kinetics. The activation energy is 24.29 kcal / mol, which is close to the activation energy of the melt polymerization. The reaction rate constant is larger than that of the latter at the corresponding temperature (extrapolated value), and the molecular weight distribution is slightly broadened. The content of cyclic oligomer The reaction temperature is increased and the reaction time is extended gradually reduced.