Synthesis and shape memory property of segmented poly(ester urethane) with poly(butylene 1,4-cyclohexanedicarboxylate) as the soft segment

Abstract

A series of thermoplastic poly(ester urethane)s (PUs) containing poly(butylene 1,4-cyclohexanedicarboxylate) (PBC) as a soft segment were prepared for shape memory materials via a two-step synthesis, with isophorone diisocyanate and 1,4-butanediol as its hard segments. The isomerization of the 1,4-cyclohexylene ring moiety (CHRM) happened during the preparation of PBC oligomers with molecular weight of 1700, 2300 and 3300 g mol⁻¹, but such phenomenon was not observed during the reaction for the synthesis of PU. The three PBC oligomers could all crystallize, but their crystallization ability was depressed after incorporation of PUs. Thermo, thermo-mechanical and mechanical properties of the corresponding PUs were studied to understand their structural information. It was found that the PU containing PBC1700 was an elastomer at elevated temperatures, and its shape memory properties were evaluated by DMA procedures. Regardless of its low degree of micro-phase separation, it was very interesting to find that the shape recovery ability of such PU was excellent, which was in contrast to traditional findings.