Polyurethane elastomers based on novel polyether macrodiols and MDI: Synthesis, mechanical properties, and resistance to hydrolysis and oxidation

Novel polyurethane elastomers based on 4,4′‐diphenylmethanediisocyanate, 1,4‐butanediol, and polyether macrodiols that have 6, 8, or 10 methylene groups between the ether oxygens were prepared by two‐step solution polymerization. Their mechanical properties and degradation resistance were compared with poly(tetramethylene oxide)‐based polyurethanes. The new polyurethanes were more resistant to hydrolysis and to hydrogen peroxide‐induced oxidation than were the poly(tetramethylene oxide) ‐based materials. The poly(octamethylene oxide) ‐based polyurethane displayed good resistance to sodium hypochlorite. 1,2‐Diaminoethane chain‐extended polyurethane–ureas were also prepared using the macrodiols poly(hexamethylene oxide) and poly(octamethylene oxide). They were not thermally processable or solvent‐castable. Bulk synthesis of novel polyether polyurethanes yielded, in some cases, materials with improved mechanical properties compared with their solution‐polymerized counterparts. The outcome of the bulk syntheses was highly dependent, however, on reaction conditions and stoichiometry.