Green Ester Synthesis Of The Lube Base Oil And Performance Study

Along environment with the wide-using lubricants and dose attention to, the environmental pollution resulted from using lubricants has been more and more considered by mankind. Since traditional lubricating oil with mineral oil taken as base oil often pollute the environment and with decreasing of petroleum resource, the development of a new biodegradable green lubricating oil replacing the mineral oil has important social and economic significance.In this paper, a series of mixed esters base oil was synthesized using renewable resource as main raw materials by two step esterifications. The basic physicochemical properties have been investigated. According to the study some basis has been provided for rational utilization renewable resource, development of the green lubricants. The main contents can be summarized as follows:Different molecular weight low molecular polymer intermediate has been prepared based on neopentyl glycol, binary acid including azelaic acid, sebacic acid and phthalic anhydride as the raw materials with different proportions, The yield can be up to 93%. A series of different viscous mixed esters base oil was got by esterification with intermediate and fatty acid oleic acid or rape oil acid, the yield of the mixed esters was over 89%. For the two reactions, p-toluensulfonic acid was used as catalyst, toluene as water carrier, reaction temperature 140-150℃, reaction time 1 h. The structure of mixed esters was studied by Infra-red spectrum.The basic physicochemical properties of rheological property, antioxidant stability, thermal stability, biodegradability and tribological property have been investigated. It has been found that the azelaic acid and sebacic acid mixed esters have wide viscosity, in the range of 100-300 mm~2/s at 40℃and viscosity indices are higher than 200, solidifying points are lower than—40℃. Before and after oxidized, acid value and viscosity of the mixed esters changed slightly which means that the mixed esters have good antioxidant stability. The decomposition temperatures are all over 300℃. Load carrying capacity P_B are bigger than 730N, and wear scar diameter are less than 0.42 mm.The biodegradable rates are higher than 95%. So they are high performance esters green lubricants, and can be used as high viscosity lubricant basic oil, viscosity modifier and viscosity index improvers. In the each properties of phthalic anhydride mixed esters, viscosity indices and biodegradable rates are relatively worse, viscosity indices are between 120-140, biodegradable rates only slightly above 73%.