Preparation of anionic functionalized ionic liquid antioxidantX C₆H₅COO for biodiesel

Two ionic liquid antioxidants (MI C₆H₅COO, Ch C₆H₅COO) were designed, and synthesized, and measured by nuclear magnetic resonance spectra and Fourier infrared spectra.The effects of two ionic liquid antioxidants on the oxidation resistance, copper corrosion and oil solubility of Jatropha biodiesel were studied.The results show that ionic liquid antioxidants can effectively improve the oxidative stability of biodiesel. When the addition amount ofMI C₆H₅COO is 0.3‰, the induction period of Jatropha biodiesel increases by 238%, exceeding the national standard (6 h). However, when the addition amount ofCh C₆H₅COO is 0.3‰, the induction period of Jatropha biodiesel increases by 141%, which does not meet the national standard. The order of oil solubility from large to small isMI C₆H₅COO > Ch C₆H₅COO > GA (raw material for synthesizing ionic liquid antioxidants).Moreover, the experiments show that the synthetic properties ofMI C₆H₅COO containing lipophilic cations in the two ionic liquid antioxidants are significantly better than those containing hydrophilic cationsCh C₆H₅COO.