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 studied 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 h to 4 h. The approximate initial pressure at the reaction temperature was 34.5 MPa (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 on 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% tetralin 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 % decalin at temperatures of 375 °C, 400 °C, 425 °C, and 450 °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.