中文摘要：

利用链长不同的含聚乙二醇单甲醚侧链的咪唑基离子液体（ILs-MPEG）改性聚乳酸（PLA），通过熔融共混法制备PLA／ILs-MPEG共混物试样。采用扫描电子显微镜观察了ILs—MPEG在PLA基体中的分散情况，应用差示扫描量热仪和热重分析仪，分别研究了ILs-MPEG对PLA的增塑作用与热稳定性的影响。结果表明，ILs—MPEG可较为均匀地分散在PLA基体中，但随着其侧链长度增加，分散性下降。ILs—MPEG能促使PLA的玻璃化转变温度（L）明显降低，表现出显著的增塑作用，同时PLA热稳定性随ILs-MPEG侧链长度增加均呈先增加后减小的趋势。其中，ILs—MPEG800能有效降低PLA的L，但对PLA的热稳定性影响最小。

英文摘要：

The ILs-MPEG, a series of imidazolium ionic liquid, containing MPEG side chain with different length were incorporated into PLA to prepare the PLA/ILs-MPEG blend samples by melt-blending. The dispersion of ILs-MEPG in PLA matrix was observed by SEM, and then the plasticization effect and thermal stability of ILs-MPEG on PLA were investigated by differential scanning caborimetry （DSC） and thermo gravimetric analysis （TGA） respectively. The results showed that ILs-MPEG could be dispersed in PLA matrix even, but the dispersion decreased with the length of MPEG side chain increasing. The glass transition temperature （T~） of PLA was effectively decreased with addition of ILs-MPEG due to the plasticization effect of ILs-MPEG, however, the thermal stabilities of PLA increased first and then decreased with the length of MPEG side chain increasing. In all of ILs-MPEG, the ILs-MPEG800 decreased Tg of PLA apparently, and had the least influence on PLA thermal stability.