Journal of Energetic Materials

The binder is an essential ingredient of solid composite propellants. Today, the industrial military scientists have been focused on finding and developing the new energetic binders to enhance the performance of the composite propellants. In this research, triblock hydroxyl-terminated polybutadiene (HTPB) with Glycidyl azide polymer (GAP) was synthesized as a new energetic binder. In the first step, PECH-HTPB-PECH copolymer was synthesized from the reaction of epichlorohydrin (ECH) with HTPB as a macro initiator in the presence of boron trifluoride etherate as the catalyst which then characterized by FTIR, 1H-NMR spectroscopies. In the second step, the GAP-HTPB-GAP copolymer was synthesized by azidation of the triblock polyepichlorohydrin (PECH) and HTPB in the presence of sodium azide and mixed solvents of dimethyl acetamide and toluene at 70⁰C in 90% yield. The effect of monomer, catalyst, and the solvents on molecular weights, as well as the yield of the copolymer (GAP-HTPB) were studied. The synthesized copolymers were identified by IR, NMR, GPC, DSC, TGA, viscosity and TLC (tin layer chromatography). In addition, after finding the curing conditions, the mechanical properties of polyurethane-based GAP-HTPB (such as tensile strength and strain) were investigated.