The Synthesis of Carboxylated PBAMO, Triazolated PBAMO and Ferrocenyl Carboxylated GAP Copolymers

Abstract

Among the components of solid rocket propellants, polymeric binder plays key role. In this work is focused on the high-energy poly[3,3-bis(3-azidomethyl)oxetane] (PBAMO), which has two azide groups. Poly(BAMO-carboxylate) and poly(BAMO-1,2,3-triazole) were successfully synthesized and characterized using various analytical techniques including Fourier-transform infrared spectroscopy, inverse-gated decoupling 13C NMR, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, calorimetry, as well as friction and impact sensitivity analysis. The experimental results show that poly(BAMO-carboxylate) have lower glass transition temperatures, higher thermal decomposition temperatures, and higher heats of combustion than those of PBAMO. Therefore, poly(BAMO-carboxylate) can be a good prepolymer candidate for designing the energetic polymeric binder. Although no significant improvement in the properties of triazolated PBAMO is observed, the study shows the effect of the triazolation of unstable PBAMO. Further investigations involved the resolve the aggregation issue and increase the burning rate of the BRC by introducing ferrocene, which is mainly used as a BRC for the carboxylated GAP polymer binder. Poly(GA-ferrocenyl butyrate) were synthesized through simple synthetic steps, and various instrumental analyses were performed. Owing to the presence of azide (-N3) and ferrocene groups, poly(GA-ferrocenyl butyrate) show two thermal decomposition temperatures, and poly(GA0.91-ferrocenyl butyrate0.09) exhibits lower glass transition temperatures than GAP.