Ameliorating the sensitivities, thermal and combustion properties of RDX by in situ self-assembly TA-Pb/Cu shells to RDX surface

Abstract

In order to ameliorate the sensitivities, thermal and combustion properties of cyclotrimethylenetrinitramine (RDX), tannic acid (TA) is used to react with lead and copper via in situ self-assembly to coat RDX for preparing RDX@TA-Pb/Cu microcapsules. The structures of RDX@TA-Pb/Cu microcapsules are characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier-transform infrared spectra (FT-IR). The surface topography of RDX@TA-Pb/Cu microcapsules are characterized by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The mechanical sensitivities and explosion points of RDX@TA-Pb/Cu microcapsules are measured to study the influence of TA-Pb/Cu shells on mechanical and thermal safeties of RDX. The non-isothermal properties of RDX@TA-Pb/Cu microcapsules are characterized by differential scanning calorimetry (DSC). The catalytic effects of TA-Pb/Cu shells on RDX are characterized by accelerating rate calorimeter (ARC). The residues of RDX@TA-Pb/Cu microcapsules after combustion in air are collected and characterized by SEM and XRD to further study the catalytic effect of TA-Pb/Cu shells. The study results show that a 150 nm TA-Pb/Cu shells are uniformly coated on RDX surfaces. The chemical structure of RDX maintains constant during in situ self-assembly coating process. The mechanical and thermal safeties of RDX are enhanced after coating with TA-Pb/Cu shells. The decomposition and combustion property of RDX can be catalyzed by TA-Pb/Cu, and the catalytic effects of in situ self-assembly coating are better than that of physical mixing. The RDX@TA-Pb/Cu microcapsules can be used in RDX based composite modified double base (CMDB) propellants.