A series of PCL /TDI / BDO polyurethanes with different compositions was synthesized by solution copolymerization. DSC

WAXD and DMTA were used to study the crystallization of PCL soft segment and mincrophase separation of the polyurethanes. It was showed that the crystallizability of PCL soft segment was depressed by the introduction of hard segment in the polyurethanes

and the soft segment was not able to crystallize until its average molecular weight was above 3000.The hard segment was able to form sufficient domains if its content was relatively high.The polyurethanes with proper compositions show good thermally stimulated shape memory effect.In addition

the influence of draw ratio

times of cyclic deformation on the shape memory behavior was also investigated.