This research investigates the stability of iodotrifluoromethane (CF3I) during storage. For CF3I to be used as a fire extinguishing agent, it must be able to be stored for long periods of time at high pressure in metal containers without degrading and losing its effectiveness. For these experiments, CF3I was placed into cylinders, along with various metal coupons. The cylinders were stored, some at elevated temperatures in an oven, for three years and then placed into storage at ambient temperature for five more years. Infrared spectroscopy was used to analyze the cylinder contents during the final five year storage at ambient temperature by comparing spectra taken before storage to spectra collected after storage. Analyses of the spectra showed the CF3I agent volume fraction changed by ± 10 % during the five years of storage at ambient temperature. In addition, for the infrared-active compounds that could be measured with the spectrometer, no new peaks developed in the spectra during ambient storage. Evaluations of the other components showed that the amount of CO2 present in the cylinders decreased by 63 % or more and the amount of CF3H decreased by 30 % or more. No new Falkene peaks developed, and changes to existing Falkene peaks did not significantly affect the CF3I agent. The combination of both copper and elevated temperatures caused degradation of CF3I, and the presence of other metals affected the severity of this degradation. In particular, the combination of copper and Nitronic 40 resulted in a complete breakdown of the CF3I agent during storage at 150 DGC.
Citation: Technical Note (NIST TN) - 1452
NIST Pub Series: Technical Note (NIST TN)
Pub Type: NIST PubsReport Number:
storage, stability, fire extinguishing agents, experiments, cylinders, decomposition products, FT-IR