【作者】 张梅； 杜春慧； 朱宝库； 徐又一；

【Author】 ZHANG Mei,ZHU Baoku,XU Youyi (Institute of Polymer Science,Zhejiang University,Key Laboratory of Macromolecular Synthesis and Functionalization,Ministry of Education,Hangzhou 310027,China)

【机构】 浙江大学高分子科学研究所,教育部高分子合成与功能构造重点实验室；

【摘要】 采用浸没沉淀相转化的方法,选取聚偏氟乙烯(PVDF)/二甲基亚砜(DMSO)/水作为制膜体系,制备了聚偏氟乙烯多孔膜.通过扫描电镜观察膜的微观结构,示差扫描量热法分析膜的热性能,红外全反射光谱和广角X射线衍射表征膜表面和本体的结晶结构,研究了浸没沉淀相转化法制备的PVDF多孔膜的多晶型结构,考察了凝固浴温度和铸膜液浓度对膜本体和表面多晶型结构的影响.结果表明所制得的膜均为本体由α晶相组成,而膜表面上α和β晶相结构同时存在,膜的结晶度和膜表面上β相的相对含量均随凝固浴温度的升高而减小,随铸膜液浓度的增加而增大.更多还原

【Abstract】 The porous poly(vinylidene fluoride)(PVDF) membranes were prepared via immersion precipitation process from PVDF/DMSO/water system.By careful manipulation of the precipitation parameters,such as precipitation temperature and PVDF concentration in casting solution,the polymorphism in the formed porous membranes was studied.Membrane morphologies were observed by field emission scanning electron microscopy (FESEM) and thermal behaviors of the membranes were examined by differential scanning calorimetry(DSC). Wide angle X—ray diffraction(WAXD) and Fourier transform infrared spectroscopy—attenuated total reflection (FTIR—ATR) were respectively used to analyze the crystalline structures of the bulks and the surface layers of the membranes.It was found that,for all the investigated cases,PVDF crystallized into a form crystalline structure in bulk membranes,while the a and(3 forms coexisted in the surface layers.Furthermore,the membrane formed at higher temperature demonstrated lower total crystallinity andβ/αphase ratio in the surface layers. The increase of polymer concentration in casting solution was found to yield the membrane with higher crystallinity andβ/αphase ratio in the surface layers.更多还原