增容PP/回收PET共混物的非等温结晶和熔融行为研究

双螺杆挤出机制备了相容剂PP-g-MA或PP-g-GMA增容PP/回收PET(r-PET)(质量比为80/20)共混物,DSC研究了相容剂含量、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。加入PP-g-MA或PP-g-GMA对PP结晶温度影响不明显或使其有所降低,与相容剂种类及其用量有关。PP-g-MA增容共混物中r-PET熔点比PP-g-GMA增容的低,表明相容剂PP-g-MA与共混物中r-PET的作用比PP-g-GMA的明显。熔融温度提高,共混物中PP结晶和熔点降低,r-PET熔融峰形和熔点取决于熔融温度。

Study on the Non-isothermal and Melting Behaviors of Compatibilized PP/recycled PET Blends

Blends of PP/recycled PET(r-PET)(80/20) compatibilized by maleic anhydride grafted polypropylene(PP-g-MA) or glycidyl methacrylate grafted polypropylene(PP-g-GMA) were prepared on a twin-screw extruder.The effects of compatilizer contents,melting temperature and time,and cooling rates on the nonisothermal crystallization and melting behaviors of the blends were investigated by differential scanning calorimetry(DSC).The results showed that the crystallization temperatures of PP were unchanged or slightly reduced for the blends compatibilized by PP-g-MA or PP-g-GMA,which depended on the compatibilizers and the content.The melting temperature of r-PET in blends compatiblized by PP-g-MA was lower than that of compatibilized by PP-g-GMA,which indicated that PP-g-MA had stronger reactivity towards r-PET compared to PP-g-GMA.The crystallization and melting temperatures decreased with the increase of pre-melting temperature,besides,the melting peak shapes and melting temperature were related to the pre-melting temperature.