PET与PLA相互部分取代的可行性研究

Study on Partially Replacing Each Other with PET and PLA

采用熔融共混方法制备了不同组成的聚对苯二甲酸乙二酯(PET)与聚乳酸(PLA)的共混物,研究了PET和PLA相互部分取代的可行性。采用力学性能测试、扫描电子显微镜和热重分析手段对PET与PLA共混物的拉伸性能、冲击性能、相容性和热稳定性能等进行了研究。结果表明,PET与PLA的共混物在350℃后才开始出现明显的热分解,具有较好的热稳定性能;当PLA或PET质量分数为20%时,PET与PLA具有良好的相容性。当PLA质量分数为20%时,共混物的拉伸强度、断裂伸长率和冲击强度比纯PET分别提高26.1%,41.7%和111.7%;PET质量分数为20%时,共混物的拉伸强度和冲击强度比纯PLA分别提高152.6%和36.6%。PET和PLA在一定程度上能相互改善对方的力学性能,可相互部分取代。

Polyethylene glycol terephthalate （PET） and Polylactic acid （PLA） were blended by melt extrusion with different mass ratio of PET and PLA, and a study on the feasibility of partially replacing each other with PET and PLA was discussed. The tensile and impact strength properties, compatibilities and thermal stabilities etc. of PET / PLA or PLA / PET blends were studied by mechanical properties tests, SEM and TG. The results show that the obvious thermal decomposition of PET/PLA or PLA/PET blends begin to occur at above 350℃ and the blends have good thermal stabilities. When the mass fraction of PLA or PET is 20%, the compatibility of PET and PLA is good. When the the mass fraction of PLA is 20%, the tensile strength, elongation at break and impact strength of PET/PLA blend compared to that of pure PET are increased by 26.1%, 41.7% and 111.7% respectively. While the mass fraction of PET is 20%, the tensile strength and impact strength of PLA / PET blend compared to that of pure PLA are increased by 152.6% and 36.6% respectively. To some extent, the mechanical properties of PET or PLA can be improved by the other which indicates that they can partially replace each other.