Synthesis of Robust Poly(BAMO-THF) Energetic Thermoplastic Elastomers by Leveraging Hard Domains

Energetic thermoplastic elastomers (ETPEs) play important roles in the study of energetic adhesives. However, the contradiction between good mechanical properties and high energy constrains its further application. Using isocyanates with different structures, a poly(BAMO-THF) (PBT) energetic thermoplastic elastomer with a disordered hard-phase structure was synthesized. The special structure imparts a high mobility and a better network relaxation of molecular chains, which results in higher toughness, lower glass transition temperature, and greater self-healing ability than commonly used ETPEs. Additionally, the large but disordered hard domains enable the prominent crystallization potential of 3,3-bis(azidomethyl) oxetane (BAMO) segments to be released. Therefore, it results in better mechanical properties at a lower content of hard segments by strain-induced crystallization, achieving a balance between mechanical and energetic properties. At 20% content of hard segments, the enthalpy of formation is 1.54 kJ/g, which makes PBT elastomers have a broader application prospect in the field of explosives and propellants. Therefore, this work is of great significance in guiding the design of multifunctional materials with high energy and high mechanical properties.