Strategically designed macromolecules as additives for high energy-density hydrocarbon fuels

• Published in: Fuel (Guildford) Vol. 270; p. 117433
• Main Authors: Mi, Ji, Ye, Dengfeng, Dai, Yitong, Xie, Hujun, Wu, Di, Sun, Haiyun, Guo, Yongsheng, Fang, Wenjun
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.06.2020; Elsevier BV
• Subjects: Accelerated tests; Additives; Antioxidants; Density functional theory; Fuels; Heat; Heat sink; Heat sinks; Hydrocarbon fuels; Hydrocarbons; Hyperbranched polymer; Initiators; Low temperature; Macromolecules; Oxidation; Oxidation tests; Oxidative stability; Polyethyleneimine; Stability; Thermal cracking; Hydrocarbon fuels; Hyperbranched polymer; Oxidative stability; Thermal cracking; Heat sink
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2020.117433

[Display omitted] •Multifunctional macromolecules were strategically designed and synthesized.•Antioxidation capability of the macromolecules was confirmed and investigated.•Heat sink enhancements for JP-10 with macromolecules as initiators were verified. To improve oxidative stability and heat sink of hydrocarbon fuels, a series of versatile macromolecular additives, BHPEI and CBHPEI, were synthesized by modification of hyperbranched poly(ethyleneimine) (HPEI). These macromolecules were used as circumstance-dependent additives in JP-10, a high energy–density hydrocarbon fuel. Each strategically designed macromolecule serves not only as a radical scavenger to improve the thermal-oxidative stability of hydrocarbon fuels at relatively low temperature, but also as a cracking initiator for heat sink enhancement as the temperature rises. According to the ASTM E1858, with the addition of BHPEI-10K at 500 ppm, the oxidation induction time of JP-10 under 175 °C could increase from 9.3 min to 14.8 min. The insoluble deposits could be reduced by 73% with the addition of 500 ppm BHPEI-10K according to accelerated oxidation tests. The superior antioxidation capability of macromolecular antioxidants were further elucidated by density functional theory (DFT) calculations. Furthermore, the BHPEI-10K performed decently as a macromolecular initiator for supercritical cracking of JP-10, with a dosage of 0.1 wt%, the conversion of JP-10 at 675 °C can be elevated from 16.4% to 33.4% and the corresponding heat sink can be improved from 1.98 MJ/kg to 2.15 MJ/kg.