The kinetic and viscosity analysis of glycidyl azide polymer spherical propellant

The kinetic and rheology processes of isothermal curing of glycidyl azide polymer (GAP) spherical propellant have been studied using isothermal rheological data. A new equation has been proposed to predict the degree of conversion of heterogeneous reaction. The kinetic and rheological parameters were experimentally determined using rheometry based on the conversion degree alpha described by storage modulus . The differential isoconversional method was used to determine the value of the apparent activation energy (E (a)). It was found that apparent activation energy varied during the curing time, but in the conversion range alpha = 0.05-0.80, E (a) is practically a constant (E (a) = 1.11 x 10(5) J mol(-1)). The kinetic model of cyanate/GAP spherical propellant system had been accomplished and showed a good agreement with experimental data. Chemorheological analysis confirmed that curing of GAP spherical propellant has two stages and the second stage has a much higher activation energy than the first one due to the different steric hindrance of two isocyanate groups. Both activation energies of two stages are much higher than that in liquid GAP. An empirical model was used to predict the variation of complex viscosity and showed a good prediction effect.