Study on bulk preparation and properties of glycidyl azide polymer with hydroxyl-terminated polyether elastomers obtained through step-wise curing process

A series of glycidyl azide polymer (GAP) with hydroxyl-terminated poly(ethylene oxide-co-tetrahydrofuran) (P(EO-co-THF)) polymer networks of various functional molar ratios (R) and different GAP contents have been prepared through the step-wise curing process. The step-wise curing condition is determined based on the thermodynamic parameters of each simplex elastomer system, which is 45 °C-3d then 60 °C-4d. The mechanical properties of the elastomers have been improved from 1.88 to 2.11 MPa in W_GAP = 50% under that condition, which is caused by the formation of the larger-sized mesh structure and in consequence the effective elastic strands increase. Meanwhile, the dynamic mechanical analysis (DMA) reveals that the glass transition temperatures of the elastomers are approximately −62.42 and −26.96 °C, respectively. Moreover, it can be concluded through DMA that the P(EO-co-THF) domains act as the main crosslinking joints compared with the GAP/N100 domains and thus cause the constrained effect. Combining extension test with DMA results, the network model of the elastomers is depicted. In addition, the thermal stabilities of the blending elastomers have also been studied, and their thermal stabilities meet the requirements of military materials.