A new process for crosslinking thermoplastic polyurethanes using rubber industry techniques

New polyurethane materials were obtained after chemical modification of a commercial thermoplastic polyurethane (TPU) using diisocyanates and diols or diamines. The reaction can be easily processed by the well‐known calendering technique often used by the rubber industry. It leads to a remarkable improvement of the thermomechanical properties of the material, due to the formation of chemical crosslinks between the TPU chains (“vulcanization”). As this new processing consists only of an intimate mixing of the starting TPU with solid reagents, followed by molding and curing stages, it allows the use of any and possibly highly reactive solid monomer (especially damines), which could not otherwise be considered except with constraining techniques like RIM; in the same way, the incorporation of organic or inorganic fillers also becomes possible.