Thermal ageing of polyurethane with hydrogenated polyisoprene soft segments

Polyurethane elastomers based on 4,4'-diphenylmethane diisocyanate, hydrogenated hydroxy terminated polyisoprene (HHTPI) and 2-ethyl-1,3-hexane diol were prepared by the classical one-shot method and subjected to thermal ageing at 150 degrees C. From the changes in the infra-red spectra, glass transition temperature, dynamic viscoelasticity and mechanical properties, it has been concluded that these HHTPI based polyurethanes were more resistant to degradation than the corresponding unsaturated hydrocarbon (i.e. polybutadiene) based materials. (C) 1997 Elsevier Science Limited.