回收PET的增粘研究

分别使用均苯四甲酸二酐（PMDA）、环氧树脂及两者的混合物作为回收PET瓶的扩链剂，利用反应挤出技术在同向双螺杆挤出机中反应，研究回收PET瓶烘干时间、扩链剂种类、扩链剂用量对PET产物的特性粘度、端羧基的质量摩尔浓度的影响。实验结果表明：均苯四甲酸二酐（PMDA）和环氧树脂均对PET有一定的扩链作用，且二者合用时扩链效果更佳，反应后PET的特性粘度由0．45dl／g提高到0．58dl／g，摩尔质量也显著提高；随着干燥时间增加，改性的回收PET样品的特性粘度增加的幅度较大；其中单独使用环氧树脂为扩链剂时，可以使反应后的PET端羧基的质量摩尔浓度显著下降。

Study on thickening of recyclable PET

The influence of the drying-time,chain extender kind and content on the intrinsict viscosity and carboxyl content of the PET was studied carefully using the extenders of Pyromellitic dianhydride(PMDA),Epoxy resin and the mixture of the both with polycondensation reactive extruder during reactive extrusion processing.Experiments showed that PMDA and Epoxy resin has an effective chain extending effect,and the effect is better when using the mixture of the both.After the reaction the intrinsict viscosity of th...