Thermal decomposition of some binary mixtures of jet fuel model compounds, including n-dodecane/n-decane, n-dodecane/n-tetradecane, n-dodecane/n-butylbenzene, n-dodecane/n-butylcyclohexane, and n-butylbenzene/n-butylcyclohexane, was studied under supercritical conditions. Thermal stressing experiments were carried out in glass tube reactors and tubing bomb reactors. Under supercritical conditions, the reaction products included not only those found in pure compound experiments, but also included the compounds unique to mixture reactions. High-pressure supercritical conditions led to the formation of significant amounts of high-molecular-weight compounds that were not observed under low-pressure conditions. The decomposition rate of one compound was affected by the addition of the second compound. (C) 2000 Elsevier Science Ltd. All rights reserved.