以液体石蜡为稀释剂,用热致相分离方法(TIPS)制备了超高分子量聚乙烯(UHMWPE)微孔膜。实验测定了UHMWPE/液体石蜡体系的相图,研究了冷却速率、UHMWPE初始浓度和分子量对膜结构及性能的影响,用扫描电子显微镜(SEM)及压汞法表征了微孔膜的微观结构及平均孔径和孔隙率,同时测试了膜的纯水通量。结果表明,UHMWPE/液体石蜡体系只存在由聚合物结晶导致的固-液相分离过程,UHMWPE初始浓度的增加或冷却速率的加快均可以导致膜平均孔径和水通量的减小;聚合物分子量影响着膜的结构与性能,聚合物分子量增加时,膜的孔径和水通量均逐渐减小。
Microporous membranes of ultra-high molecular weight polyethylene (UHMWPE) were prepared by thermally induced phase separation (TIPS), using liquid paraffin (LP) as diluent. The diagram of the UHMWPE/LP system was etermined. The influence of some factors as polymer concentration, polymer molecular weight and cooling rate on the performance and the morphology was investigated. The results shows that the UHMWPE/ LP system undergo the solid-liquid phase separation (polymer crystallization) rather than liquid-liquid phase separation. The pore size and porosity decreased with increasing the polymer concentration and the cooling rate. The membrane prepared with the higher molecular weight polymer showed not only the larger pore size but also higher porosity and water permeability.