Molecular-beam mass-spectrometric study of the flame structure of composite propellants based on nitramines and glycidyl azide polymer at a pressure of 1 MPa

A study was performed of the chemical and thermal structure of flames of model composite propellants based on cyclic nitramines (RDX and HMX) and an active binder (glycidyl azide polymer) at a pressure of 1 MPa. Propellant burning rates were measured. The chemical structure of the flame was studied using molecular-beam mass spectrometry, which previously has not been employed at high pressures. Eleven species (H$_2$, H$_2$O, HCN, N$_2$, CO, CH$_2$O, NO, N$_2$O, CO$_2$, NO$_2$, and nitramine vapor) were identified, and their concentration profiles, including the composition near the burning surface were measured. Two chemical-reaction zones were observed. It was shown that flames of nitramine/glycidyl azide polymer propellants are dominated by the same reactions as in flames of pure nitramines.