CAJ | 학술논문

对聚偏氟乙烯(PVDF)/碳酸二苯酯(DPC)体系,采用热致相分离(TIPS)法制备了PVDF微孔膜.通过稀释剂的溶度参数对体系的相容性进行分析,热力学相图和不同PVDF质量浓度下制备的微孔膜断面照片均证明该体系具有较宽的液-液相分离区.PVDF/DPC体系偏晶点对应的PVDF浓度约为质量分数56%,低于此浓度体系降温后先发生液-液相分离,随着PVDF浓度的增大,微孔膜断面结构由双连续结构转变为蜂窝状结构,且膜孔孔径减小,高于此浓度体系降温后只发生固-液相分离,微孔膜断面呈块状紧密堆积结构.较快的冷却速率有利于低PVDF浓度时较小孔径膜和高PVDF浓度时较小球粒尺寸膜的生成.
대취편불을희(PVDF)/탄산이분지(DPC)체계,채용열치상분리(TIPS)법제비료PVDF미공막.통과희석제적용도삼수대체계적상용성진행분석,열역학상도화불동PVDF질량농도하제비적미공막단면조편균증명해체계구유교관적액-액상분리구.PVDF/DPC체계편정점대응적PVDF농도약위질량분수56%,저우차농도체계강온후선발생액-액상분리,수착PVDF농도적증대,미공막단면결구유쌍련속결구전변위봉와상결구,차막공공경감소,고우차농도체계강온후지발생고-액상분리,미공막단면정괴상긴밀퇴적결구.교쾌적냉각속솔유리우저PVDF농도시교소공경막화고PVDF농도시교소구립척촌막적생성.
Polyvinylidene fluoride (PVDF) microporous membranes were prepared via thermally induced phase separation (TIPS) method of PVDF blended with diphenyl carbonate (DPC). The compatibility between PVDF and diluent was analyzed in the view of solubility parameter. A larger liquid - liquid phase separation region was obtained from PVDF/DPC system, which was confirmed by the thermodynamic phase separation of PVDF/DPC system and the SEM photographs of cross - section of PVDF membranes at different polymer mass fractions.The polymer mass fraction on the monotectic point of PVDF/DPC system was 56%. When quenching the PVDF/DPC solution with a polymer mass fraction lower than that in ice water, the liquid - liquid phase separa-tion occurred prior to polymer crystallization. With the increase of polymer mass fraction, the morphology of the resulting membrane changed from a typical bicontinuous structure to a celluar structure, and the pore size of membranes decreased. However, only the polymer crystallization occurred if further increasing the polymer mass fraction, which resulted in the block close packing structure. In addition, the faster cooling rate resulted in smaller pore sizes at polymer concentration of 30% and smaller spherulite particles at polymer concentration of 70%.