Ionic liquids (ILs), instead of the classical organic solvents, have shown great improvements in chemical processes. Herein, Water-insoluble alkyl- and benzyl-substituted imidazolium bis(trifluoromethanesulfonyl)imides as non-volatile and thermostable solvents were employed in the direct polycondensation of l-lactic acid (LLA). The effects of monomer concentration, reaction temperature and miscibility between the ILs and poly(l-lactic acid) (PLLA) were comprehensively investigated. Biodegradable PLLA with weight-average molecular weight as high as 132 kDa was synthesized. Compared to melt-polycondensation of LLA, far higher molecular weight could be achieved via the solution polycondensation of LLA in ILs since the viscosity of the polymer melt could be significantly reduced based on the dilution effect of ILs. Polycondensation kinetics of LLA in bulk and in an IL demonstrated that the IL could accelerate the polycondensation of LLA. Influence of lactide, the main by-product, on the polycondensations of LLA was also studied kinetically.

离子液体 (IL) 代替了经典的有机溶剂，在化学过程中表现出了很大的改进。在本文中，水不溶性烷基和苄基取代的咪唑鎓双（三氟甲磺酰基）酰亚胺作为非挥发性和热稳定溶剂用于l-乳酸 (LLA)的直接缩聚。单体浓度、反应温度和离子液体与聚（l）之间的混溶性的影响-乳酸）（PLLA）进行了全面的研究。合成了重均分子量高达 132 kDa 的可生物降解的 PLLA。与 LLA 的熔融缩聚相比，通过 LLA 在 IL 中的溶液缩聚可以实现更高的分子量，因为基于 IL 的稀释作用可以显着降低聚合物熔体的粘度。LLA 本体和 IL 的缩聚动力学表明 IL 可以加速 LLA 的缩聚。还动力学研究了主要副产物丙交酯对 LLA 缩聚的影响。