回收PET共混物的非等温结晶和熔融行为

采用双螺杆挤出机制备了聚丙烯(PP)/回收聚对苯二甲酸乙二酯(r-PET)、r-PET/马来酸酐接枝PP(PP-g-MAH)和r-PET/甲基丙烯酸缩水甘油酯接枝PP(PP-g-GMA)共混物,并研究了共混物组成、熔融温度与时间以及降温速率对共混物非等温结晶与熔融行为的影响.结果表明,r-PET与PP共混,结晶温度均提高,这与组分间起到异相成核诱导结晶作用有关.r-PET结晶温度随PP-g-MAH用量增加而降低,但受PP-g-GMA用量影响较小;r-PET可提高PP-g-MAH结晶温度,但降低PP-g-GMA结晶温度.熔融温度提高,共混物中PP结晶温度和熔点均降低,r-PET熔融峰形和熔点取决于共混物的熔融温度及界面相互作用.

Non-isothermal and melting behavior of recycled PET blends

Blends of polypropylene/recycled polyethylene terephthalate (PP/r-PET), r-PET/maleic anhydride grafted PP (PP-g-MAH) and r-PET/glyceryl methacrylate grafted PP (r-PET/PP-g-GMA) were prepared by the aid of a twin-screw extruder. The effects of blend composition, fusion temperature, fusion time and cooling rate on non-isothermal crystallization and melting behavior of the blends were studied by differential scanning calorimetry. The results indicate that in the case of blending r-PET with PP, the crystallization temperatures of both r-PET and PP rise due to the heterogeneous nucleation effect between the components. The crystallization temperature of r-PET decreased with increasing PP-g-MAH dosage and is slightly influenced with r-PET/PP-g-GMA dosage. r-PET is able to raise crystallization temperature of PP-g-MAH but lower that of PP-g-GMA. When raising fusion temperature, the crystallization temperature and melting point of PP in the blend reduce. The shape of melting peak and melting point of r-PET in the blends are dependant on the blends' fusion temperature and the interfacial interaction.