Experimental and Theoretical Aspects of Segmented Poly(ester urethane)s properties. Conformational Transitions in Solid State and Solution

Segmented poly(ester urethane)s containing hard and soft segments, were obtained from aromatic diisocyanates with 4,4'-dihidroxydiethoxydiphenyl sulphone as chain extender, and poly( ethylene glycol) adipate using a multistep polyaddition process. Transition temperatures by differential scanning calorimetry and thermo-optical analysis were employed to characterize polyurethane materials. Changes in the conformation of these polyurethanes were analyzed also, by viscometer measurements in N,N-dimethyl-formamide. The obtained data revealed that the thermal curves are influenced by the soft and hard segment structures in the temperature range studied.