Thermal Decomposition Kinetics of Kerosene-Based Rocket Propellants. 3. RP-2 with Varying Concentrations of the Stabilizing Additive 1,2,3,4-Tetrahydroquinoline

The thermal stability of the kerosene-based rocket propellant RP-2 with varying concentrations of the stabilizing additive 1,2,3,4-tetrahydroquinoline (THQ) was investigated. The mixtures (by mass) were RP-2 + 0.1% THQ, RP-2 + 0.5% THQ, RP-2 + 1% THQ, and RP-2 + 5% THQ. These were thermally stressed in sealed stainless-steel reactors at 400 C for 1-4 h. The approximate initial pressure at the reaction temperature was 34.5 M Pa (5000 psi). The extent of decomposition as a function of time was determined by analyzing the thermally stressed liquid phase by gas chromatography. The results with each THQ mixture were compared to the thermal stability of neat RP-2 under the same conditions. The thermal stability of the mixtures showed a clear dependence upon the concentration of THQ. For example, the addition of 5% THQ slowed the rate of decomposition by approximately an order of magnitude, and the addition of 0.5% THQ slowed the rate of decomposition by approximately 50%. We also report the results of another potential stabilizing additive, trans-decahydronaphthalene (decalin). We tested the thermal stability of RP-2 + 5 mass % decalin at temperatures of 375, 400, 425, and 450 degrees C. Unlike THQ, the addition of 5% decalin to RP-2 had no significant effect on the thermal stability of RP-2 in this temperature range.