Rheokinetic characterization of polyurethane formation in a highly filled composite solid propellant

摘要

The cure kinetics of a composite solid propellant premix based on ammonium perchlorate, hydroxyl-terminated polybutadiene (HTPB) and diisocyanate system was investigated using a rheometer. The cross-linking kinetics of HTPB resin in the presence of tolylene diisocyanate in a propellant was studied under isothermal conditions in the temperature range of 60-70 degrees C by rheometry. The kinetic parameters of the curing reaction were calculated from the rheological measurements. These parameters were derived by a multiple regression analysis using a classical phenomenological model expanded by an empirically derived diffusion factor. The obtained kinetic parameters were used to generate a master equation capable of predicting the reaction profile at any given temperature. Excellent match between observed and predicted cure profiles in the entire temperature range validated the adequacy of the model.