Thermal decomposition of fluorinated polymers used in plasticized explosives and munitions

A number of military explosives and munitions employ fluorinated polymers as binders or components, e. g., PBXN-5. To determine potential environmental releases during disposal operations, the thermal decomposition of the fluorinated polymers Viton A, Kel-F, and Teflon were examined alone and in combination with the explosive HMX. Although PBXN-5 only contains 5 % by weight Viton A, laboratory prepared analogs were made with 5 % polymer as well as with 50 % polymer to ensure polymer decomposition products could be detected. Under air and under nitrogen decomposition was examined by SDT [simultaneous differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)], TGA-infrared (IR) spectrometry, and pyrolysis gas chromatography with mass spectrometric analysis (GC-MS). All three techniques, SDT, TGA-IR, and pyrolysis GC-MS, suggest that decomposition of HMX could be completed at low temperature before polymer decomposition ensues. To confirm this observation, pyrolysis GC-MS was performed at temperatures below 350 degrees C since above this temperature all three polymers exhibited some fluorinated decomposition products. image