Structure‐property relationships in N‐vinyl pyrrolidone grafted onto segmented polyurethanes

Linear unsaturated segmented polyurethanes have been modified by grafting onto their backbones N‐vinyl pyrrolidone chains. The thermal behaviour of the unmodified and graft copolymers was investigated using TGA and DSC/DTA instruments in a nitrogen atmosphere. Viscosity measurements show that the graft copolymers have relatively lower limiting viscosity numbers compared to the original polyurethane. X‐ray studies show that the copolymers are amorphous while electron microscopy studies show an increase in spherical domain size in the graft copolymers. The modified polymers possess better mechanical properties.