界面增容剂的结构对PLA/PP共混体系界面状态及性能的影响

The influence of the structure of the interfacial compatibilizer on the interfacial state and performance of the PLA/PP blends

通过在聚乳酸(PLA)和聚丙烯(PP)共混体系中分别引入马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)和甲基丙烯酸缩水甘油酯接枝乙烯-辛烯共聚物(POE-g-GMA),制备出具有不同结构及性能的共混材料(PLA/PP/POE-g-MAH,PLA/PP/POEg-GMA),并采用转矩流变仪、扫描电子显微镜、差示扫描量热仪、平板流变仪及电子万能试验机等研究了不同界面增容剂的结构对PLA/PP共混体系界面状态及性能的影响。结果表明,POE-g-MAH和POE-g-GMA均可改善PLA与PP的相界面形态,但与POE-g-GMA相比,POE-g-MAH的界面催化效率更高,对PLA/PP共混体系增容效果更好,其可诱导PLA与PP在界面处形成微交联结构,增强PLA与PP的界面相互作用,改善材料的机械性能,当添加4wt%的POE-g-MAH时,PLA/PP/POE-gMAH共混物的拉伸强度达29.7 MPa,断裂伸长率提升至39.3%,较PLA/PP样品提高了8倍;并且共混材料的冲击强度随着POE-g-MAH含量的增加而增加,当其添加量为6wt%时,材料冲击强度达30.1 kJ/m^(2),材料具有较好的刚韧平衡性。

Maleic anhydride grafted ethyleneoctene copolymer(POE-g-MAH)and glycidyl methacrylate grafted ethyleneoctene copolymer(POE-g-GMA)were introduced into the polylactic acid(PLA)/polypropylene(PP)blends to prepare different structures and performance blended materials(PLA/PP/POE-g-MAH,PLA/PP/POE-g-GMA).The effects of compatibilizers with different structures on the regulation behavior of interface state and performance of PLA/PP blends were investigated by the torque rheometer,DSC,SEM,flat rheometer and electronic universal testing machine,etc.The results showed that both POE-g-MAH and POE-g-GMA could improve the interface morphology of PLA and PP,but compared with POE-g-GMA,the interface catalytic efficiency of POE-g-MAH was higher,which could induce PLA and PP more compatible,and catalyzed the formation of micro cross-linking structure at the interface between PLA and PP,which enhance the interfacial interaction between PLA and PP,and finally improved the mechanical properties of the material.When 4 wt%POE-g-MAH was introduced,the tensile strength of the PLA/PP/POE-gMAH blend reached 29.7 MPa,and the elongation at break increased to 39.3%,which was 8 times higher than that of PLA/PP sample.Also,the impact strength of the samples enhanced with the increase of the content of POE-gMAH,and when its addition amount was 6 wt%,the impact strength of the material reached 30.1 kJ/m^(2),which had a good balance of rigidity and toughness.