Evaluating the bis-isoxazole core for energetic heterocyclic-based oligomers

Abstract

Development of energetic polymers is at the forefront of the energetics research enterprise. Formulations having high energy density as well as robust safety are goals that can be realized with implementation of new energetic polymers that target performance and mechanical properties. Presented herein are a series of oligomers synthesized from the small molecule BIDO (1) as our group's first attempt at making heterocyclic based energetic polymers without sensitive explosophores. Crystallographic investigation of the BIDO core with surrogate addends demonstrated the significant stacking ability of the BIDO core. Synthesis of four unique oligomers (3–6) is presented and characterized by spectroscopic and thermochemical measurements. Polymerization of 6 was demonstrated and tested for T_g and thermal sensitivity, and Shore A hardness. The polymer 7 exhibits a T_g value (−18 °C), close to the operating range of other energetic materials, a Shore A hardness of 81, and thermally stable up to 320 °C.