乙烯-丙烯酸甲酯共聚物与POE协同增韧PLA的研究

Study on Synergistic Toughening of PLA by Ethylene-methyl Acrylate Copolymer and POE

采用熔融共混法制备了聚乳酸(PLA)、乙烯-辛烯共聚物(POE)和乙烯-丙烯酸甲酯共聚物(EMA)的三元共混物,通过万能拉伸试验机、简支梁冲击试验机、扫描电子显微镜(SEM)和偏光显微镜(POM)对共混物的力学性能、微观形貌和结晶行为等进行表征,重点研究了不同比例的POE和EMA对PLA的增韧效果。研究结果表明,PLA/POE共混物具有较差的界面相容性,而在PLA/POE/EMA中,可以观察到PLA/POE的界面相容性得到了提高;当POE与EMA质量比为2/3时,两种PLA/POE/EMA共混物(质量比95/2/3和90/4/6)的断裂伸长率是纯PLA的3倍和7倍,缺口冲击强度是纯PLA的5和7倍,说明POE和EMA能够协同增韧PLA;POE对PLA具有诱导结晶的作用,而在PLA/POE/EMA中,这种诱导作用减弱。

Ternary blends of polylactic acid(PLA),ethylene-octene copolymer(POE)and ethylene-methyl acrylate copolymer(EMA)were prepared by melt blending.The mechanical properties,microscopic morphology and crystallization behavior of the blends were characterized by universal tensile testing machine,simply supported beam impact testing machine,scanning electron microscope(SEM)and polarized light microscope(POM).The toughening effect of different proportions of POE and EMA on PLA was mainly studied.The results show that PLA/POE blends have poor interfacial compatibility,while in PLA/POE/EMA,the improved interfacial compatibility of PLA/POE can be observed.When the mass fraction ratio of POE to EMA is 2/3,the elongation at break of the two-component PLA/POE/EMA(95/2/3 and 90/4/6)blends is 3 times and 7 times that of pure PLA,and the impact strength is 5 and 7 times that of pure PLA.It shows that POE and EMA can synergistically toughen PLA.POE has the effect of inducing crystallization on PLA,while in PLA/POE/EMA,this induction effect is weakened.