Mechanistic study on oxidative degradation and deposition of exo-tetrahydrodicyclopentadiene

The advancement of propulsion systems accelerates the exploitation and application of various high-energy-density (HED) fuels, and yet severe oxidative-fouling hinders the adoption of such fuels in thermal-stressed conditions. In this work, we investigated the overall thermal-oxidative degradation and deposition process of a typical HED fuel, exo-tetrahydrodicyclopentadiene (exo-TCD), known as JP-10 (NHOC = 39.6 MJ/L), with the presence of oxygen. The oxidation mechanism of exo-TCD at relatively low temperatures is illustrated on the basis of experimental and computational results. For the first time, the chirality of oxidation products has been discussed, revealing the potential impact of radical configuration on the oxidation process of exo-TCD. Besides, an in-depth investigation on the deposition formation process was carried out by analyzing the structure and composition of polymeric macromolecules with the assistance of TG-IR-GC/MS technique. The oxidative deposition of exo-TCD is illustrated with a three-step mechanism of oxidation, polymerization, and deposition. The solubility of macromolecular species formed upon oxidation is decisive for the deposition propensity of fuels. This work aims to provide a theoretical and methodological basis for the future study on the oxidative stability of HED fuels.

Automated summary

This study investigates the overall thermal-oxidative degradation and deposition process of a typical high-energy-density fuel, exo-tetrahydrodicyclopentadiene (exo-TCD), with the presence of oxygen. The oxidation mechanism of exo-TCD at relatively low temperatures is discussed, along with the potential impact of radical configuration on the oxidation process. In addition, the deposition formation process is analyzed, revealing a three-step mechanism of oxidation, polymerization, and deposition.