Thermal properties and morphology of poly(ester-urethanes) prepared from polycaprolactone-diol

The soft segment crystallinity and morphology of poly(ester-urethanes) (PEU s) based on poly(epsilon-caprolactone) (PCL) as a soft segment and an aliph atic diisocyanate in the hard segment were studied. It was found that the r estriction of the crystallization of the PCL soft segment depends on the ha rd segment concentration, the length of the soft segment, and the total mol ecular mass of the PEUs. The PEU based on a low molecular mass PCL (M=2000) is an amorphous elastic material during a long time after casting from sol ution or after melt crystallization. A soft-hard segment endothermal mixing transition (T-mix) of about 70-80 degrees C is observed in the DSC curves of this PEU sample.