Novel graphene iron organic nanocomposites for enhancing combustion and safety properties of AP-HTPB propellant

Abstract

Graphene iron tannate and graphene iron gallate nanocomposites (G-D-Fe and G-M-Fe) were designed, synthesized and characterized to deal with the performance requirement of AP-HTPB propellent. Effects of the G-D-Fe and G-M-Fe on the thermal decomposition of AP, laser ignition, combustion and safety characteristics of AP-HTPB propellant were explored. By taking Catocene as the benchmark (156.80 mJ), the G-D-Fe improves the safety performance of propellant, and the ignition energy (E50) is increased by 17.25 mJ. Besides, the G-D-Fe and G-M-Fe have positive effects on enhancing the burning rate and the reducing the pressure exponent of propellant, and the influence of G-D-Fe is more significant. The burning rate enhances from 13.87 to 16.92 mm·s−1 at 15 MPa and the pressure exponent reduces from 0.47 to 0.32 in 4∼15 MPa after the introduction of G-D-Fe. The catalytic mechanism of G-D-Fe were analyzed on the basis of flame morphology, combustion wave structure, in-situ FTIR and gas-phase FTIR-MS. The outstanding catalytic property of G-D-Fe is due to its promotion effect on AP pyrolysis and the formation of stable products, which is conductive to the intense reactions of gas products and the thermal transmission between burning surface and gas phase, and reflecting in the significant enhanced burning rate.