Synthesis of Propargyl-Terminated Polybutadiene Acrylonitrile and Properties of the Resulting Polytriazole Elastomers

In composite solid propellants, liners are critical for ensuring structural integrity and reliability, yet traditional polyurethane systems face limitations, including moisture sensitivity and plasticizer migration. To address these challenges, a novel propargyl-terminated polybutadiene acrylonitrile (PTBN) binder is synthesized and cured via click chemistry. The curing kinetics, mechanical properties, and migration resistance of the resulting polytriazole elastomers are systematically investigated. Optimal mechanical performance is achieved at an azide-to-alkyne molar ratio of R = 1.0, yielding a maximum tensile strength of 2.83 MPa. The introduced cyano groups significantly enhance compatibility with azide curatives and reduce plasticizer migration compared to conventional systems. Furthermore, incorporation of 3 wt% montmorillonite creates nanoscale barrier effects that synergistically improve migration resistance while maintaining mechanical integrity. This PTBN-based polytriazole system represents a significant advancement in liner technology, offering superior curing controllability and migration resistance for next-generation solid rocket motor applications.