Polyurethane Membranes

Poly(ether urethane) membranes were synthesized from toluene diisocyanate (TDI), and poly(propylene-ethylene) glycol. Catalysts, chain extenders, solvents, or other reagents were not used during the preparation to make the biomedical grade membranes. Density, water content, oxygen diffusivity, and the surface thrombogenicity were examined and the presence of the extractables was searched. A decrease in density and an increase in water content and oxygen permeability was observed with an increase in polyol content of the mem branes. Extraction of leachables in solvents was observed which was prevented by accelerated aging that had no effect on the other properties examined.