丙酮/DMF二元溶剂体系聚氨酯湿法膜的结构与性能

摘要

采用不同比例 N,N-二甲基甲酰胺(DMF)和丙酮组成的混合溶剂溶解热塑性聚氨酯(PU),并通过非溶剂致相转变的方法制备了聚氨酯多孔膜.研究了丙酮用量对PU膜的表观结构、微观结构、力学性能和透湿性能的影响.结果表明,随着混合溶剂中丙酮用量的增加,PU膜横截面孔径和连通孔径均变大,连通孔数量减少,PU膜透湿性能和力学性能增加.%Polyurethane(PU)films were prepared via a non-solvent induced phase separation by dissolving thermoplastic polyurethanes in a mixed solvent system composed of various ratios of N,N-dimethylformamide and ac-etone. The effects of acetone content on the morphology,microstructure,mechanical properties and moisture perme-ability of PU films were investigated. The results showed that,in the presence of acetone,the pore size of PU film was increased while the pore number was reduced proportionally.Furthermore,the moisture permeability and tensile strength of PU films were enhanced with the addition of acetone.