回收PET的扩链增粘改性研究

Study on Chain Extension and Tackifying Modification of Recycled PET

采用均苯四甲酸二酐(PMDA)对回收PET(rPET)进行扩链增粘,从特性粘度和端羧基含量的变化考察了PMDA的扩链效果,并借助DSC研究了扩链剂对rPET结晶行为的影响。结果表明:PMDA扩链剂对rPET具有良好的扩链增粘作用,当PMDA用量为1.25%时,rPET的特性粘度达到0.813dL/g,满足作为工程塑料使用的粘度要求;rPET的结晶行为与其特性粘度有关,随着特性粘度升高,结晶度降低,结晶更加困难。

Recycled PET(rPET) was modified with pyromellitic dianhydride(PMDA) to achieve a chain extension and tackifying,which was characterized by intrinsic viscosity and carboxyl values.The effect of chain extension on crystallization behavior was studied with the help of DSC.The results show that pyromellitic dianhydride has a good chain-extension effect,and when the content of PMDA is 1.25%,the intrinsic viscosity of rPET is 0.813dL/g,which has met the request of rPET used as engineering plastics.The crystallization behavior of rPET is related with its intrinsic viscosity.With the increase of intrinsic viscosity,the crystallinity of rPET decreases and crystallization becomes more difficult.