Improvement of mechanical characteristics of glycidyl azide polymer binder system by addition of flexible polyether

Two kinds of flexible chain polymer, poly(ethylene oxide-co-tetrahydrofuran) (P(EO-co-THF)) and polyalkylene oxide (PAO), were chosen to improve the mechanical properties of the network of glycidyl azide polymer (GAP)–based elastomers. The mechanical properties of the GAP binder system at 25 and −40 °C can be improved effectively. The effects of P(EO-co-THF) and PAO on the network parameters, hydrogen bonding effect, and crystallization property were studied to determine the enhancement mechanism. Based on the results, it can be concluded that for copolyurethane elastomers prepared with PAO content less than 15 wt % and P(EO-co-THF), the mechanical properties were enhanced by the reduction of bulk side groups in GAP, which improved the chemical crosslinking density, hydrogen bonding effect in elastomers, and the motility of the molecular chains, while for elastomers prepared with more than 15 wt % PAO, the crystallization of the PAO segments played a major role in the improvement of mechanical properties.