POLYURETHANES

摘要

The present invention relates to cross-linked polyurethanes or polurethane-ureas and processes for their preparation. The polyurethane comprises a soft segment formed from (a) at least one polyether macrodiol and/or at least one polycarbonate macrodiol; and (b) at least one polysiloxane macrodiol, at least one polysiloxane macrodiamine and/or at least one silicon-based polycarbonate; and a hard segment formed from (c) a polyisocyanate and (d) at least one di­-functional chain extender, wherein the segments are further formed from (e) at least one cross-linking agent. The Polyurethanes are biostable and creep resistant which makes them useful in the manufacture of biomaterials and medical devices, articles or implants, in particular orthopaedic implants such as spinal disc prostheses.