Glycidyl Azide Polymer and Its Polyurethane Network: Optimized Synthesis and Characterization

Glycidyl azide polymer (GAP) is a next-generation energetic binder that has garnered significant attention for applications in the aerospace industry owing to its high heat of combustion, high specific impulse, low sensitivity to detonation, low glass transition temperature, and excellent compatibility with energetic oxidizers. In the present study, the synthesis of GAP was optimized using a two-step procedure, involving solvent-free polymerization of epichlorohydrin (ECH) and subsequently aqueous azidation using phase-transfer catalyst TBAB in water with a high yield of 95%. This procedure was suitable for green chemistry due to not using organic solvents in two steps. The structure and thermal properties of the product were fully determined using various analytical methods (IR, NMR, GPC, DMA, and TGA). Synthesized GAP exhibited the following characteristics: viscosity 4000 mPa s, hydroxyl value Hv = 55 mgKOH/g, water content <0.2%. Upon cross-linking with the curing agent N100/IPDI, the copolyurethane-GAP achieved physical and mechanical properties suitable for application as an energetic binder.