| abstract |
Partially crosslinked polyurethane polymers comprising diisocyanates and aliphatic hydrocarbon soft segments together with short chain diol chain extenders and multifunctional amine and/or alcohol crosslinkers are described to provide properties useful in the production of medical implant devices Polyurethane polymers with useful properties such as heart valves. The polymer has an unexpected linear elastic region in the range of 5-100%, preferably 10-35%. In some embodiments, the polyurethane is a thermally convertible gel formulation that can be converted to a liquid formulation by prolonged heating to make the polymer suitable for solvent processing techniques, such as casting, spraying, spinning, and the like. The present invention also provides living hinge polyurethane polymers that can be thermally modified from gel to liquid and reaction injection molded (RIM) polyurethanes with increased flex life. |