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Influence of Hard Segment Structure on Degradation of Cross-linked Poly(ether urethanes) Elastomers

Cross-linked polyurethanes (PUs) based on poly(1,4-butane diol), 4,4′-diphenylmethane diisocyanate, 1,6 hexamethylene diisocyanate with a varied content and nature of the hard segment and a constant soft segment length were hydrolytically degraded in distilled water at 37°C. The incubation of polymer samples took place over a period of maximum 30 days. The changes in tensile strength and morphology of PU samples were tested after a particular period of incubation. Degradation was determined by FTIR-ATR and by analyzing mechanical properties. It is demonstrated that the degree of degradation of PUs in distilled water is dependent on the degree of cross-linking and nature of the diisocyanates and chain extenders.