POLYURETHANES AS BIOMEDICAL MATERIALS

Polyurethane films were prepared using diphenylmethanediisocyanate [MDI] or hexamethylenediisocyanate [HDI] and poly(propylene-ethylene)glycol, in order to test them as biomedical materials specifically for use as skin grafts. Other ingredients such as catalysts, chain extenders, solvents, etc., where not used in order to obtain medical purity. Mechanical properties, oxygen permeation and blood compatibility of these films were examined. Tensile strength, ultimate elongation and elastic modulus values were calculated. An increase in ultimate elongation and a decrease in tensile strength were observed when the amount of isocyanate-containing compound was decreased in the prepared polymers. Oxygen permeability values also increased with an increase in polyol content of the prepared films. Blood compatibility tests showed that the film surfaces do not have thrombogenicity and can be considered biocompatible.