A new biomedical polyurethane with a high modulus based on 1,4-butanediisocyanate and epsilon-caprolactone

A new approach to the synthesis of biomedical polyurethanes based on epsilo n-caprolactone and 1,4-butanediisocyanate with a high modulus, has been dev eloped. By chain extending an epsilon-caprolactone prepolymer with a long u niform-size diisocyanate block, a segmented polyurethane with uniform-size hard segments was obtained. It shows excellent mechanical properties; an ex tremely high modulus of 105 MPa and a tensile strength of 35 MPa. The polym er is soluble at high concentrations in various volatile solvents such as c hloroform and 1,4-dioxane. By a combination of salt-leaching and freeze-dry ing, porous materials have been obtained in which macropores ranging in siz e from 150-300 mu m are highly interconnected by micropores. The material s hows a sufficiently high compression modulus of 200 kPa and appears to be s uitable for biomedical applications such as meniscal prostheses. (C) 1998 K luwer Academic Publishers.