OPTICAL-PROPERTIES OF ENERGETIC MATERIALS FROM INFRARED-SPECTROSCOPY

A method of determining infrared (25-18 mu m) optical properties of di electric, crystalline, particulate solids such as energetic materials was developed based on KBr-FTIR (infrared) spectroscopy. Two technique s (spectral subtraction and baseline shifting) were used to account fo r light scattering by the KBr matrix. An independent CO2 laser-spatial filtering measurement was also developed to check the spectral subtra ction approach. The method is demonstrated here for the oxidizer ammon ium perchlorate (AP). The Rayleigh-Gans limit of light scattering theo ry was exploited to establish a relationship between the apparent KBr- pellet absorption coefficient and the intrinsic Ar absorption coeffici ent. Dispersion theory was used to determine refractive index from the absorption index for AP, Conventional (nonscattering) FTIR spectrosco py was also used to determine the absorption coefficient for the commo n solid propellant binder hydroxyl-terminated polybutadiene.