Thermal stressing of a Jet A fuel containing triphenylphosphine (TPP) as an additive results in a significant enhancement in thermal oxidative stability. Efforts to elucidate the mechanism(s) responsible for the observed thermal oxidative stability enhancement are reported. Data presented for the reaction of TPP with molecular oxygen show two pathways to be important. In particular, in nonpolar solvents and in the presence of BHT, the data are consistent with TPP playing an oxygen scavenging role via operation of an electron-transfer-initiated-oxygenation chain mechanism. The significances of these findings to the potential development of a new generation of thermal oxidative stability enhancing additives is discussed.

Model autoxidative, radiolytic, and product studies are presented which explore the potential of 1,2,5-trimethylpyrrole (TMP) as an oxygen-scavenger additive for future jet fuels. The oxygenation of TMP in cyclooctane at 120 °C is consistent with a mechanism for the initial stages of the reaction being an ETIO reaction. This study provides new insights for the development of oxygen scavengers which may be useful for future jet fuels.

The need for the development of jet fuels that are oxidatively and thermally stable to 480°C (900°F) has been previously detailed (Edwards and Liberio, 1996). Such a fuel is commonly referred to as JP-900. It is our belief that a new class of additives can be developed which, when added to JP-8, will provide both the oxidative and thermal stability requirements of JP-900. Our most recent data is presented which explores the potential of 1,2,5-trimethylpyrrole (TMP) as a potential oxygen scavenger.