Synthèse et propriétés de poly(uréthannes-b-diènes hydrogénés)

α-ω hydroxy-terminated oligo-dienes, both butadiene and isoprene, hydrogenated at different ratios, were polymerized with diphenylmethane diisocyanate and 1,4-butanediol. Dynamic and static mechanical studies were made on the segmented polyurethanes. Those synthesized from oligo (1,4-butadiene) show the decrease of damping peak and a second relaxation due to semi-cristalline structure of soft blocks after their hydrogenation. On the other hand, the hydrogenation of oligo (1,2-butadiene) renders polyurethanes with better elastomeric properties, that is, the relaxation of soft blocks at lower temperature, and the good mechanical and thermal properties at higher temperatures. This can be explained by the modification attributed to the better block segregation between the hydrogenated soft blocks and the urethane hard blocks.