氯化聚氯乙烯膜微观结构及其性能影响因素的研究

Study on the influence factors of properties and microstructure in chlorinated polyvinyl chloride membrane

采用非溶剂致相分离法制备了氯化聚氯乙烯(CPVC)膜,考察了铸膜液的聚合物含量与温度、凝胶浴温度与凝胶浴中溶剂含量对CPVC膜微观结构及其性能影响.结果表明,铸膜液的聚合物含量与温度、凝胶浴中溶剂质量分数在60%以下及凝胶浴温度为20℃以下时,CPVC膜的断面均为致密皮层、指状孔及大孔支撑层构成的非对称膜;凝胶浴中溶剂质量分数达到80%及凝胶浴温度在30℃以上时,CPVC膜断面变为多孔皮层和海绵状结构构成的非对称膜,在所研究范围内,CPVC膜对牛血清蛋白(BSA)的截留率在87%以上,膜的水通量范围为111~1 287.89L/(m^2·h).与文献比较,CPVC膜的过滤性能及机械性能均远优于聚氯乙烯(PVC)膜.

In this paper,chlorinated polyvinyl chloride（CPVC）membrane was prepared by non-solvent induced phase separation method,then the influence of membrane processing conditions（polymer content of the casting solution,the casting solution temperature,the gel bath composition and the the gel bath temperature）on microstructure and performance of CPVC membrane were investigated.It was found that different polymer content and temperature of the casting solution and temperature in the research area,or the solvent content in the gel bath was lower than 60%,or the temperature of the gel bath was below20 ℃,the CPVC membrane,which had dense layer surface and macroporous support layer in the crosssection and nonporous surface,was asymmetric.In addition,when the gel bath composition reached 80%,or the gel bath temperature was above 30 ℃,large conical macroporous membrane structure was changed into sponge-like structure,and small holes appeared in the membrane surface.It was found that the rejection was always avbove 87%,and the minimum water flux was 111L/（m2·h）in the research area,while the maximum water flux was 1 297L/（m2·h）.The results showed that the properties of CPVC membrane were much better than PVC membrane.