本文以可降解聚乳酸为膜材料，采用水溶性稀释剂二甲基亚砜（DMSO），实现了复合相分离法制备结构可调控的聚乳酸分离膜。重点考察了铸膜液温度和凝固浴温度对其结构及渗透性能的影响。结果表明，当凝固浴温度接近浊点温度时，相分离过程中主要以NIPs过程为主，形成了指状孔和大空腔结构，聚乳酸分离膜的纯水通量较小；牛血清蛋白的截留率较高。当凝固浴温度低于浊点温度时，体系发生TIPs和NIPs复合相分离过程，制备的聚乳酸分离膜具有双连续和指状孔结构，聚乳酸分离膜纯水通量较大，牛血清蛋白的截留率略有降低，但都在66%以上。当铸膜液温度接近浊点温度时，体系发生TIPs和NIPs复合相分离过程，制备的聚乳酸膜具有多孔的表面膜结构，表面膜孔与支撑层之间的连通性较高；随着铸膜液温度的增加，膜表面孔径减小，聚乳酸分离膜纯水通量降低，由610 L/（h•m2）降低至27.6 L/（h•m2）;牛血清蛋白截留率增加，由61%提高至 84%。

In this paper, based on water-solubility diluent (DMSO), biodegradable poly (lactic acid) membrane was prepared via complex phase separation. The effect of coagulation bath temperature, casting solution temperature as important factors on structure and performance of membrane were investigated. The results showed that when coagulation bath temperature was near to cloud point temperature, the effect of NIPs was dominating. The prepared membranes possess the structure of fingerlike pores and macrovoids with low flux and high the retentions of BSA. When coagulation bath temperature was lower than cloud point temperature, complex phase separation occurred in the phase separation process. The prepared membranes possess the structure of fingerlike pores and interconnected bicontinuous structure with high water flux and lower the retentions of BSA. The retentions of BSA was above 66% .When casting solution temperature was near to cloud point temperature, complex phase separation occurred in the phase separation process. The prepared membranes possess porous skin layer, good connectivity between membrane pores and support layer. With the increase of casting solution temperature, the  membrane pore size decreased and the water flux  decreased sharply from 610 L/（h•m2）to 27.6 L/（h•m2）. The retentions of BSA  increased from 61%to 84%.

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