The synthesis of bis-m-dibromdibenzoat-, bis-p-dibrombenzoat esters of ethylene-glycol with ionic-fluid catalysts and their study in diesel fuel

Bis-m-dibromdibenzoat and bis-p-dibromdibenzoat esters of ethylene-glycol with the yield of 92, 88 % correspondingly have been synthesized based on the p-brombenzoic, m-brombenzoic acids and ethylene-glycol in the ratio of 2:1.2, at the 110 оС temperature and with 6–7 hours duration in the presence of ionic-fluid catalyst of n-methylpyrrolidon-hydrosulfate. The physical-chemical parameters of synthesized compound esters have been defined and their structure identified spectrally. Due to the electrophilic (Cl, Br) heteroaromatic acids in the synthesized esters, the resin content (sedimentation capacity) of the components in the diesel fuel reduces. The decrease of amount of resin in the synthesis of esters activates them as the antioxidants in the diesel fuel. These esters used in 100 ml diesel fuel in 0.004 % concentration reduced the sedimentation at 120 оС temperature approximately for five times. Synthesized compound esters have been tested on the increase of resistance of the diesel fuel against thermooxidation. Thus, it is justified that the esters of synthesized ethylene-glycol may be used in the presence of a catalyst of hydrosulfate of n-methylpyrrolidon for the increase of thermooxidative stability of the diesel fuel.