A series of segmented thermally stimulated shape-memory polyurethanes, which consist of polyethylene adipate glycol (PEA)as the soft segment and 4,4'-diphenylmethane diisocyanate(MDI)-1,4-butanediol(BDO)-DPA(which consists of ring components) as the hard segment were synthesized by one-step polymerization. The shape recovering rates on repeated deformation of the PUs with different hard segment contents were examined. In addition, the thermal properities of the PUs were analysed by using DSC and the micro m...