Preparation of PVDF-HFP Microporous Membranes via the Thermally Induced Phase Separation Process

作者：Zhenyu Cui, You‐Yi Xu, Li-Ping Zhu, Huiyu Deng, Jianyu Wang, Bao‐Ku Zhu · 发表于：Journal of Macromolecular Science Part B · 年份：2008 · DOI：10.1080/00222340802561532 · 被引用次数：18 · 研究领域：Membrane Separation and Gas Transport、Membrane Separation Technologies、Advanced Sensor and Energy Harvesting Materials

The thermally induced phase separation (TIPS) process was employed to prepare poly (vinylidene fluoride-co-hexafluoropropylene; PVDF-HFP) microporous membranes using sulfolane as the diluent. The phase diagram of the PVDF-HFP/sulfolane system was drawn and analyzed. The effects of polymer content in casting solution and cooling rate on the cross-sectional morphology, crystallinity, crystal structure, and porous structure of the resulting membranes were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and a mercury porosimeter, respectively. The mechanical properties of the membranes were evaluated by tensile tests. It was found that a solid-liquid phase separation occurred in the PVDF-HFP/sulfolane system. Spherulites and “net-shaped” structures coexisted in the obtained membranes. Polymer content and cooling rates had some influences on the crystallinity, porous structure, and mechanical properties of the membranes, but no influence on the polymer crystal structure of the membranes.