PET—PEG嵌段共聚物的热性能和流变性

酯交换法合成了一系列不同ＰＥＧ含量的ＰＥＴ－ＰＥＧ嵌段共聚物，并以差示扫描量热法研究了这些嵌段共聚物及纯ＰＥＴ的热性能。用毛细管流变仪研究了不同温度和不同长径比条件下它们的流为性能。

THERMAL AND RHEOLOGICAL PROPERTIES OF PET-PEG COPOLYMERS

Polyethylene glycol (PEG) of low molecular weight was successfully introduced into polyethylene terephalate (PET) to polymerize PET-PEG block copoly-mer. And the samples with different PEG contents were studied using differential scanning calorimeter (DSC) and capillary rheometer. The DSC curves and the rheological properties of PET-PEG copolymers under different temper-ature (when the ratio of length to diameter (L/D) was 50) and at different L/D at 270C were obtained. It was found that the contents of PEG had great influence on PET-PEG copolymcrs' properties. The copolymers had lower viscosity at higher shear rate and relatively lower non-Newton index compare with the pure PET which indicated that the copoly-mers had larger elasticity. Activation energy for flow was changed with the PEG contents and it reached the maximum at 30 wt% PEG contents while the minimum at 15 wt% PEG contents. Some suggstions were given for the spinning practice based on the melt rheological properties.