节点文献
PET回收料的改性研究
Chain Extension of Recycled PET by Reactive Extrusion
【作者】 高琨；
【作者基本信息】 北京工商大学 ， 称材料加工工程， 2010， 硕士
【摘要】 分别使用均苯四甲酸二酐(PMDA)、环氧类扩链剂及两者的混合物作为回收聚对苯二甲酸乙二醇酯(PET)料的扩链剂,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料烘干时间、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及结晶性能的影响。实验结果表明:随着干燥时间增加,改性的回收PET料的特性粘度增加的幅度较大;PMDA和环氧类扩链剂均对PET有一定的扩链作用,且二者合用时扩链效果更佳, PET的特性粘度由0.45dl/g提高到0.58dl/g,粘均相对分子质量也显著提高;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,结晶度有所提高。合成新型扩链剂,反应型含磷化合物10-(2,5-二羧基丙基)-9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO-ITA);反应型含磷中间体10-(2’,5’-二羟基苯基)-9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(ODOPB);分别将两种合成扩链剂单独使用和联用方法与回收PET料进行扩链反应,研究扩链剂用量对PET产物的增粘效果。实验结果表明:当DOPO-ITA的含量为2%时,PET的特性粘度最大为0.52dl/g,比直接挤出PET的粘度增加0.14dl/g,增幅36.8%,比用扩链剂PMDA和环氧类扩链剂联用的增幅28.9%还高,说明DOPO-ITA对rPET有很好的增粘效果。当ODOPB的含量为2.5%时,PET的特性粘度最大为0.47dl/g,比直接挤出PET的粘度增加0.07dl/g,增幅17.5%,说明ODOPB没有ITA对PET回收料的扩链效果明显。
【Abstract】 The influence of the drying-time,chain extender kind and content on the intrinsict viscosity ,carboxyl content and crystal capability 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 the intrinsict viscosity of the PET was increaseing with the longer drying-time.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 the PET increased from 0.45 dl/g to 0.58dl/g, the molecular weight was also increased abviously. The corbosyl content decreased abviorsly and the crystal degree raised when using epoxy resin.With different contents of DOPO-ITA and ODOPB and the mixture of the both as chain extender, reactive extrusion process for recycled PET flakes was conducted by means of a co-rotating twin screw extruder. The results showed: DOPO-ITA has the best effective chain extending effect. The best intrinsict viscosity of the PET is 0.52 dl/g when using the content of DOPO-ITA is 2%. But the intrinsice viscosity of the PET is 0.47dl/g when using ODOPB.The effect is worse than DOPO-ITA.