Preparation of microporous PVDF membrane via tips method using binary diluent of DPK and PG |
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Authors: | Yuanhui Tang Yakai Lin Wenzhong Ma Ye Tian Jian Yang Xiaolin Wang |
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Affiliation: | 1. State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, People's Republic of China;2. Tianjin Institute of Medical Equipment, Tianjin 300161, People's Republic of China |
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Abstract: | Microporous polyvinylidene fluoride (PVDF) membrane was prepared via thermally induced phase separation (TIPS) method using a binary diluent of diphenyl ketone (DPK) and 1,2‐propylene glycol (PG). The phase diagram for the PVDF/binary diluent of DPK and PG system was measured in the range of the PG/DPK mass ratio changing from 0 to 2/3. Then the effects of the PG/DPK mass ratio and the PVDF concentration on membrane cross‐section structures and tensile strength were also investigated. The results showed that the addition of PG brought about a shift of the cloud point curve to a higher temperature and the extension of the liquid–liquid phase separation region to a higher polymer concentration. Therefore a bicontinuous cross‐section structure was obtained when the PG/DPK mass ratio was 3/7 and the polymer concentration was 30 wt %. As an increase of the PG/DPK mass ratio, the tensile strength increased gradually at a fixed PVDF concentration. Moreover, for the same PG/DPK mass ratio, the cross‐section microstructure changed from a bicontinuous or a cellular structure to a spherulitic structure, and the tensile strength increased drastically as the polymer concentration increased from 20 to 50 wt %. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 |
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Keywords: | polyvinylidene fluoride thermally induced phase separation membrane binary diluent 1,2‐propylene glycol |
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