Polyurethanes

Partially crosslinked polyurethane polymers comprising diisocyanates and aliphatic hydrocarbon soft segments with a short-chain diol chain extender and a multifunctional amine and/or alcohol crosslinker to provide a polyurethane polymer with useful properties for the production of medical implant devices such as heart valves, are described. The polymers have an unexpected linear elastic region ina range from 5 - 100% and preferably between 10 - 35%. In some embodiments the polyurethanes are a thermally convertible gel formulation which may be converted to a liquid formulation by extended heating to render the polymer suitable for solvent processing techniques such as casting, spraying, spinning, etc. The invention also provides for living hinge polyurethane polymers which are thermally modifiable from a gel to a liquid and reaction injection moulded (RIM) polyurethanes with an enhanced flex life. 描述了包含二异氰酸酯和脂族烃软链段以及短链二醇扩链剂和多官能胺和/或醇交联剂的部分交联的聚氨酯聚合物，以提供具有用于生产医学植入装置如心脏瓣膜的有用性质的聚氨酯聚合物。所述聚合物具有5-100%，优选10-35%范围内的意想不到