EVA-g-GMA的制备及其对PLA/PHBV共混物性能的影响

摘要

通过熔融聚合法先制备了乙烯-醋酸乙烯酯接枝甲基丙烯酸缩水甘油酯(EVA-g-GMA),采用红外光谱仪和核磁共振对EVA-g-GMA的结构进行了表征.然后将不同质量分数的EVA-g-GMA加入到聚乳酸/聚(3-羟基丁酸酯-co-3-羟基戊酸酯)(PLA/PHBV)共混物中,对共混物的性能进行研究.结果表明:GMA成功接枝到EVA上,随着EVA-g-GMA加入量的增加,PHBV与PLA的Tg升高,结晶度逐渐下降;分散相在PLA基体中的分散逐渐均匀,粒径减小,相界面渐渐模糊;在EVA-g-GMA加入后,共混物粘度升高,断裂伸长率和冲击强度分别可达290.9％和43.5KJ.m-2,三元共混物的水蒸气阻隔性相对于PLA/PHBV略有下降.综合考虑各种因素,EVA-g-GMA的加入使得PLA/PHBV的整体性能得到极大改善.%Glycidyl methacrylate grafted poly (ethylene-co-vinyl acetate) (EVA-g-GMA) was prepared and the structure of EVA-g-GMA was characterized by FT-IR andNMR.Then,the effects of EVA-g-GMA on thermal behavior,morphologies,rheological properties,mechanical and barrier properties were studied by differential scanning calorimetry (DSC),scanning electron microscope (SEM),capillary rheometer,universal testing machine and humidity chamber.The results show that GMA has been grafted to EVA,and Tg of PLA/PHBV composites increases with the addition of EVA-g-GMA.However,the crystallinity shows an opposite trend to the change of Tg.SEM photographs suggest that the incorporation of EVA-g-GMA decreases the particle sizes of disperse phase and achieves a blurry phase interface and homogeneous dispersion.Besides,the viscosity of PLA/PHBV/EVA-g-GMA gives a slight enhancement and elongation at break and impact strength reach to 290.9％ and 43.5KJ·m-2,respectively.It is worthy to note that the water barrier property of ternary blends declines slightly.Based on comprehensive consideration,the overall performance of PLA/PHBV is significantly enhanced by the incorporation EVA-g-GMA.