Influence of mixed diluents on ethylene chlorotrifluoroethylene co-polymer ( ECTFE) microporous membrane prepared via thermally induced phase separation (TIPS) was studied. The effect of different nonsolvents on crystallization of ECTFE/dibutyl sebacate (DBS)onsolvent systems was investigated. Based on the analysis of the compatibility of ECTFE/DBSonsolvent systems and the cross-section morphologies of membrane, it was found that the phase separation of the ECTFE/DBS system was changed from solid-liqiud to liquid-liquid when triphenyl phosphite (TPP) was added. A bicontinuous ECTFE membrane structure with uniform pore size was obtained at the ratio of TPP : DBS =4 : 6. The thermodynamic phase diagram of ECTFE/DBS/TPP system showed a large liquid-liquid phase separation region and a monotectic point at the polymer concentration as high as 50%.%研究了混合溶剂对热致相分离法制备乙烯-三氟氯乙烯共聚物(ECTFE)微孔膜的影响,考察了不同非溶剂对ECTFE/癸二酸二丁酯(DBS)体系结晶趋势的影响.通过相容性分析及ECTFE微孔膜断面结构的观察,非溶剂亚磷酸三苯酯(TPP)的加入能使ECTFE/DBS体系从固-液相分离转变为液-液相分离.当非溶剂与溶剂的质量比比例(TPP∶DBS)为4∶6时,可制得孔径均匀的双连续结构ECTFE微孔膜.此比例下的热力学相图显示,ECTFE/DBS/TPP三组分体系具有较宽的液-液相分离区,该体系偏晶点所对应的ECTFE质量分数高达50％.
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