APPLICATION OF FT-IR TECHNIQUES FOR IDENTIFICATION OF DIFFERENT POLYMERS USED IN THE COATING PROCESS OF ENERGETIC MATERIALS

摘要

Coating techniques for producing plastic bonded explosives (PBX) consist of coating the crystals of energetic materials, such as octahydro 1,3,5,7 - tetranitro - 1,3,5,7 - tetrazocine (HMX) or hexahydro -1,3,5 - trinitro - 1,3,5- triazine (RDX), with polymers, such as fluorpolymers, polyurethanes, elastomers and others. The granular product (explosive/plastic) represents one of the most important processes in obtaining pressed explosive charges by means of hydraulic press, where the pressed granular product has an explosive content above 95% of weight. The characteristics of the polymer play an important role in the final properties of PBX. Therefore, this work involves the characterization of HMX and RDX explosive samples coated with polyurethane and fluoelastomer polymers, using Fourier transform infrared spectroscopy (FT-IR) of transmission and/or photoacoustic detection (PAS). It was observed that it is not possible to identify the presence of the polymers by means of the transmission technique (KBr pellets). Using the casting film transmission technique it was possible to identify the presence of polyurethane and fluorelastomer, however this technique requires the separation of the polymer and explosive. PAS technique was better because it allowed to identify both the polymer and explosive without previous sample preparation. The widening of the bands near the 1200 cm~(-1) suggests the presence of fluorelastomer and the band near 1700 cm~(-1) shows the polyurethane absorption's.