Microporous Film, Made from β-Crystalline Phase Polypropylene

Abstract

Abstract A new type microporous polypropylene film was prepared simply by biaxial drawing of β-crystalline phase polypropylene The effect of draw ratio on the pore size distribution, ethanol sorption, and porosity, as well as β-α transformation during drawing were studied For the purpose of improving its hydrophilicity ion and solute permeability, the plasma graft-polymerization technique was utilized The resulting film showed much higher permeability toward Na+, Mg++ and urea, being 3.2 × 10−6, 5.8 × 10−8 and 1.75 × 10−6 cm2/min, respectively, than the original one and had better dimensional stability.