Thermal decomposition properties of PBT-based energetic thermoplastic polyurethane elastomers with high content of soft segment

The 3, 3-bis (azidomethyl) oxetane/tetrahydrofuran (BAMO-THF) copolyether (PBT) bonded energetic thermoplastic polyurethane elastomers (ETPUE) were synthesized through prepolymer method using PBT and 4, 4'-diisocyanato-methylene dicyclohexane as raw material. Its glass transition temperature (T_g) was obtained by DSC, and the thermal decomposition behaviors were studied by TG and TG-FTIR-MS. The results show that with an increase in the content of hard segment, the T_gs and T_gh of soft segment and hard segment of ETPUE shift temperature upwards. The thermal decomposition process can be divided into four stages. The activation energy of thermal decomposition reaction for each stage is different. The first stage corresponds to the scission of the N₃ bonds. And then the main chain decomposition is induced.