Method for the preparation of new segmented polyurethanes with high tear and tensile strengths and method for making porous scaffolds

Abstract

The invention presents a new method to prepare biomedical polyurethanes with high tensile and tear strengths. Such polyurethanes are especially interesting for making foams thereof, e.g. as meniscus implants. A new method, applicable to the biomedical polyurethanes, has been found to make such foams, that can be used as scaffolds. This method is based on salt leaching and phase separation.

1 . Method for preparing a polyurethane using a macrodiol, a diisocyanate and a chain extender, the chain extender comprising a (cyclo)aliphatic diol, said method comprising: 
 a) reacting either the macrodiol or the chain extender with an excess of diisocyanate, resulting in a macrodiisocyanate or a reaction product of the diisocyanate and the chain extender,    b) removing the remaining unreacted diisocyanate,    c) reacting, the macrodiisocyanate with the chain extender or the macrodiol with the reaction product,    wherein a) and c) are carried out in the substantial absence of a catalyst.