Composite Solid Rocket Propellant Based on GAP Polyurethane Matrix with Different Binder Contents

Different GAP-based CSRP samples with different binder contents were prepared and compared with that of conventional HTPB propellant. The crosslinker mixture of trimethylol propane (TMP) and butane diol (BD) was used in the GAP matrix beside the addition of dibutyltin dilaurate (DBTDL) to ensure cross-linking and curing completion of the prepared CSRP. The viscosity and hardness of all prepared formulations were monitored continuously during the curing process. The mechanical characteristics of cured samples were tested. The burning rate at operating pressure and specific impulse were measured, while the theoretical specific impulse (I_sp) was calculated by ICT code and compared with the measured results. According to the results, DOA was found to be a suitable plasticizer for GAP when using in propellant.The mechanical properties of CSRP with 25% GAP can produce the optimum mechanical behavior, which is close to that of HTPB-based CSRP. The optimum GAP-based formulation is one candidate to replace the traditional HTPB-based CSRP with high burning rate for some applications.