Synthesis and Properties Study of Ploy(Difluoroaminomethyl‐3‐Methyloxetane)‐Based Triblock Copolymers for Energetic Binder

ABSTRACT Difluoroamino (–NF 2 ) is one of the ideal energetic functional groups for enhancing the overall performance of solid propellants. Its strong oxidizing properties reduce the average molecular weight of combustion products and increase the specific volume of combustion gases, thereby significantly boosting the energy release level of solid propellants and demonstrating tremendous application potential. In this study, hydroxyl‐terminated polyether (HTPE) was copolymerized with 3‐difluoroaminomethyl‐3‐methyloxetane (DFAMO) via cationic ring‐opening copolymerization to form the PDFAMO‐HTPE‐PDFAMO triblock copolymer, which achieves coordinated optimization of energy and mechanical properties. PDFAMO‐HTPE‐PDFAMO retains the benefits of HTPE's low glass transition temperature and favorable thermal stability, with a peak decomposition temperature of 257.1°C and a corresponding decomposition enthalpy of 1385.64 J/g. Combined with three model‐free kinetic calculation methods to obtain key thermal performance parameters such as activation energy and frequency factor. Furthermore, TG‐FTIR technology was utilized to validate the thermal decomposition process and elucidate the decomposition mechanism, which is divided into a two‐stage pyrolysis process: initial decomposition of the difluoroamino groups followed by scission of the polymer backbone. These results demonstrate the potential of PDFAMO‐HTPE‐PDFAMO tri‐block copolymer as the energetic propellant binder.