凝固浴温度对复合相转化PVC/PVB膜结构与性能影响  

Effect of Coagulation Bath Temperature on Structure and Properties of PVC/PVB Film Prepared by Compound Phase Transformation Method

作　　者：秦青青 秦舒浩 杨园园 杨敬葵 雷婷 武晓 Qin Qingqing;Qin Shuhao;Yang Yuanyuan;Yang Jingkui;Lei Ting;Wu Xiao(Guizhou Material Industry Technology Research Institute,Guiyang 550025,China)

机构地区：[1]贵州省材料产业技术研究院,贵阳550025

出　　处：《工程塑料应用》2021年第6期89-94,共6页Engineering Plastics Application

基　　金：贵州省科技项目(黔科合支撑[2020]4Y021,黔科合成果[2020]3Y007,黔科合基础[2018]1089,黔科合平台人才[2020]6022)。

摘　　要：以水溶性脂γ-丁内酯(GBL)和N,N-二甲基乙酰胺(DMAc)为混合稀释剂,利用复合相转化法制备了聚氯乙烯(PVC)/聚乙烯醇缩丁醛(PVB)共混超滤膜,考察了凝固浴温度对PVC/PVB共混超滤膜微观结构、孔隙率、力学性能、纯水通量、截留率和抗污染性能的影响。结果表明,复合相转化法可以有效抑制指状孔的生长,PVC/PVB膜断面孔由致密皮层、指状孔与海绵孔构成;成膜过程中,相分离发生了非溶剂致相分离(NIPS)和热致相分离(TIPS)两个过程,凝固浴温度升高,NIPS过程对膜的影响大于TIPS过程的影响,加快了非溶剂水在PVC/PVB聚合物溶液中的溶解速度,同时提高了溶剂与非溶剂水之间的传质速度,表皮层的成型加快,膜皮层逐渐变厚,使高浓度聚合物在溶剂中的溶解速度越慢,膜断面的指状孔由大变小,海绵孔结构增多,提高了共混膜的力学性能;共混膜的抗污染性能受凝固浴温度变化较小,凝固浴温度为35℃时,膜的抗污染指数最优。Polyvinyl chloride(PVC)/polyvinyl butyral(PVB)blend ultrafiltration membrane was prepared by using the mixed diluents ofγ-butyrolactone(GBL)and N,N-dimethyl acetamide(DMAc)through compound phase transformation method.The effects of coagulation bath temperature on the microstructure,porosity,mechanical properties,pure water flux,entrapment rate and resistance to the influence of the pollution were investigated.The results showed that the growth of fingerlike pores was effectively inhibited by the compound phase transformation method.The broken face of PVC/PVB film was composed of dense cortex,fingerlike pores and sponge pores.During film forming process,the phase separation occurred at non-solvent induced phase separation(NIPS)and thermally induced phase separation(TIPS)two process.As the coagulation bath temperature increases,the influence of NIPS process on the membrane is greater than that of TIPS process,which accelerates the dissolution rate of non-solvent water in PVC/PVB polymer solution and improves the mass transfer rate between solvent and non-solvent water.The formation of the epidermis is accelerated,and the membrane layer is gradually thickened,which makes the dissolution rate of the high concentration polymer in the solvent slower.The fingerlike pores in the membrane cross section become smaller and the sponge pore structure increases,which improves the mechanical properties of the blend film.The anti-fouling performance of the blend film is not affected by the coagulation bath temperature,and the anti-fouling index of the film is the best when the coagulating bath temperature is 35℃.

关 键 词：聚氯乙烯 聚乙烯醇缩丁醛 超滤膜 复合相转化法 凝固浴温度 

分 类 号：TQ028.8[化学工程]