氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物及其马来酸酐接枝共聚物增韧聚对苯二甲酸乙醇酯共混材料的辐射效应

采用双螺杆熔融共混的方法制备了含三羟甲基丙烷三丙烯酸酯(TMPTA)的聚对苯二甲酸乙二酯/氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物（PET/SEBS）和聚对苯二甲酸乙二酯/马来酸酐接枝氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物（PET/SEBS-g-MAH）共混材料，并在Co-60源中对其进行辐照。 通过对共混材料的力学性能、相态结构测和凝胶含量分析，对比研究了辐射对以上2种共混材料结构及性能的影响。 扫描电子显镜观察和凝胶含量分析结果表明，在适量TMPTA存在时，辐射有效地改善了PET/SEBS体系的相容性。 冲击强度的变化证实了这种增容效应，当SEBS的质量分数为20%、TMPTA质量分数为1%，经50 kGy辐照后，冲击强度达到17.3 kJ/m2。 当在SEBS分子链上引入马来酸酐官能团，辐照后，体系的相态结构变化并不明显，冲击强度最大值仅为11.5 kJ/m2，明显低于不含马来酸酐官能团的体系。

Radiation Effects on Styrene Ethylene Butylene Styrene and Its Maleic Anhydride Grafted Copolymer Toughened Polyethylene Terephthalate Alloys

The alloys of polyethylene terephthalate(PET)/styrene ethylene butylene styrene(SEBS)/trimethylol propane trimethylacrylate(TMPTA) and PET/SEBS-g-MAH(maleic anhydride)/TMPTA were prepared by melting blending with a twin screw extruder and irradiated by a Co-60 source. The effects of irradiation on the structure and properties of blends were studied through characterizations of mechanical properties, phase morphology and gel content analysis. The results of scanning electron microscopy(SEM) and gel extraction indicated that irradiation effectively improved the compatibility of PET/SEBS blends in the presence of an appropriate amount of TMPTA, which was ascribed to the generation of a new copolymer comprising both chains of SEBS and PET at the interface area. The compatibility was confirmed by the changes of impact strength as well. When the mass fraction of SEBS and TMPTA were 20% and 1% respectively, the impact strength of the blend reached 17.3 kJ/m2 after irradiation at 50 kGy. The introduction of maleic anhydride groups to SEBS chains did not change the phase structure obviously, but the maximum of impact strength was only 11.5 kJ/m2 in this case, significantly lower than that of the blends without maleic anhydride groups.