干/湿相转化法制备偏氟乙烯-六氟丙烯共聚物对称微孔膜

Preparation of poly(vinylidene fluoride-co-hexafluoro propylene)-based symmetric microporous membranes by a dry/wet phase inversion method

用干 /湿相转化成膜法制备了偏氟乙烯 -六氟丙烯共聚物 (PVDF -HFP)为基材的对称微孔膜 ,该膜可用于塑料锂离子电池的聚合物电解质 .通过扫描电镜、孔隙率和湿膜电导率 ,主要考察了成膜工艺中干态处理的环境因素 ,温度和湿度对所制微孔膜的形态和性能的影响 .研究结果表明 ,在较低的温湿度下干态处理铸膜液 ,易形成小颗粒为主的对称性微孔膜 ;而在较高的温湿度下随处理时间的延长 ,形成的微孔膜从有致密皮层的不对称结构转变为对称有缺陷海绵体结构 .采用FT -IR研究了成膜机理 。

Poly(vinylidene fluoride-co-hexafluoro propylene)-based symmetric microporous membranes have been prepared by a dry/wet phase inversion method. The materials produced find application as hybrid electrolyte matrixes for plastic lithium-ion batteries. The effects of air-drying conditions (temperature, humidity and drying time) on morphology and properties of the microporous membranes have bean investigated by SEM, porosity and conductivity. The results demonstrate that the air-drying process at low temperature and humidity gives rise to symmetric membranes with small particle size. At high temperature and humidity however the morphology of the membranes changes from an asymmetric one with dense layers to a symmetric sponge containing defects as the drying time is extended. The mechanism of membrane formation as investigated by FT-IR suggests that a γ-type crystalline phase is formed after the low temperature drying process.