Molecular Inclusion of Small Aging Products into the Hexanitrohexaazaisowurtzitane (CL‐20) Lattice: Part I, Infrared Spectra

Abstract

AbstractAccelerated aging studies of β CL‐20 thin films deposited on glass surfaces in different environments (N2, air, air/water) were conducted. Samples were analyzed with attenuated total reflectance infrared (ATR‐IR) spectroscopy. Spectral features of molecular lattice inclusions in CL‐20 films aged in an air/water environment were observed. The features occurred after β CL‐20 polymorph transformation to α CL‐20 and were accompanied by the appearance of lattice water peaks. To assist ATR‐IR peak assignment, density functional theory studies were performed, and IR spectra of α CL‐20 lattice inclusions of small molecules that were identified as degradation products of CL‐20 were computed. Simulated spectra of NO2, HNCO, N2O, and CO2 incorporated into partially hydrated α CL‐20 matched the experimental spectrum of β CL‐20 thin films aged in air/water.