PLA/POE-g-MAH共混材料的辐照效应研究

Research on the irradiation effects of PLA/POE-g-MAH blends

采用熔融共混的方法制备了PLA/POE-g-MAH/TAIC共混材料,并进行γ射线辐照。通过力学、凝胶和扫描电镜测试,研究了共混材料的辐照效应。结果表明,辐照可以对该体系进行界面原位增容,从而提高其力学性能。当重量配比为50/50/3的PLA/POE-g-MAH/TAIC共混材料在30 kGy剂量下辐照时,其缺口冲击强度得到明显提升,达到20.8 kJ/m2,约为未辐照时的2.5倍。扫描电镜、凝胶抽提的测试结果与力学性能的变化相一致。当共混物在适当剂量下辐照时,由于界面处包含两相链段的共聚物的生成,体系的相容性得到改善。在发生冲击破坏时,共混材料中产生大量的屈服形变,表现出明显的韧性断裂特性。

Polyblends of PLA/POE-g-MAH/TAIC were prepared by melt blending and gamma-rays irradiation. Mechanical characterization, gel extraction and scan electron microscope （SEM） were employed to research the irradiation effect of the blends. The results indicated that PLA/POE-g-MAH/TAIC blends could be in situ compatibilized by irradiation and the mechanical properties were enhanced. When irradiated at a absorbed dose of 30 kGy, the notched impact strength of the blend with the weight ratio of 50/50/3 was obviously improved to 20.8 kJ/m^2, which was about 2.5 times of the value without irradiation. The conclusions of scan electron microscope （SEM） and gel extraction were agreed with changes of mechanical properties. Since a new copolymer comprising both chain segments of PLA and POE was formed at the interphase area at certain absorbed dose, the compatibility of the blend was improved, and obvious features of ductile fracture was confirmed by lots of yield deformation when the samples were impacted.