Synthesis and characterization of polyurethane with poly(ether-ester) diols soft segments consisted by ether and ester linkages in one repeating unit

Development of controllable, versatile and robust degradable polyurethane (PU) is of continued attraction regarding its wide application in the field of biology and medicine. Herein, new degradable poly(ether-ester-urethane) (PEEU) with amorphous and hydrophilic poly(1,5-dioxepan-2-one) (PDXO) diols as the soft segments and 4,4-diphenylmethane diisocyanate (MDI) and butane-1,4-diols (BDO) as the hard segments was synthesized by the one-shot two -step method in a controllable manner. The degradation behavior of PEEU with various compositions in vitro was investigated by observing the changes of weight loss, molecular weight and surface morphology during the 140 days of degradation. The weight loss and degradation rate of PEEU were faster than that of PU with semi-crystallized poly( ε -caprolactone) diols as soft segments and a surface to bulk degradation process was observed by scanning electron microscopy (SEM). In addition, the weight loss decreased by increasing the hard segments composition and the weight loss was mainly from the hydrolysis of ester linkages.