Research On The Synthesis And Performance Of Trimethylolpropane Trioleate

Traditional mineral lubricating oil is derived from non-renewable petroleum resources and its poor biodegradability,easy to accumulate makes it facing great environment challenge.It is extremely urgent to develop new biodegradable lubricants to replace traditional mineral lubricating oil.So vegetable oil as raw material to develop gree lubricant instead of traditional mineral oil gets more and more popular.Due to its excellent lubricating properties,good thermal stability,biodegradability and high viscosity index,synthetic easter oil can work in harsher conditions.Therefore trimethylolpropane trioleate?TMPTO?synthesized from trimethylolpropane and oleic through esterification reaction has a broad application prospect.Because of the presence of multiple unsaturated fatty acids?linoleic acid;C18:2 and linolenic acid;C18:3?in crude oleic acid,the properties of TMPTO synthesized by crude oleic acid were influenced.In this paper,the catalytic performance of Pd-Pb/SiO₂ catalyst prepared by equal volume impregnation method was studied in the fixed bed.The effect of Pd loading and Pb addition on the catalytic activity were investigated and the process conditions were optimized.Based on the activity evaluation data and the calculation of double bond length,in the selective hydrogenation of polyunsaturated fatty acids,conjugated fatty acids with higher hydrogenation were first generated by the positional isomerization of double bonds and then hydrogenated to the target product oleic acid.The industrial process of catalytic synthesis easter oil was complicated and it was difficult to be separated from the mixture,so the quality of the production was influenced.A new method of autocatalytic esterification to synthesize TMPTO was investigated.Through the designing of experimental instruments and the optimization of reaction conditions,under the temperature of 230 ^oC,mole ratio of acid/alcohol of 3.3:1,reaction time of 6h,pressure of0.09 MPa,the yield of TMPTO was over 96%.Activated carbon,molecular distillation and MgO were used to the decolorization process and deacidification process of the product.The results showed that activated carbon exhibits obvious decolorizaton effect.The acid value of the product was reduced from 20.63 mgKOH/g to 0.27 mgKOH/g by molecular distillation and MgO adsorption deacidification.The results of FT-IR showed that the structure of the product was not changed after the post-processing refining,so the treatment process was aviliable.The properties of TMPTO synthesized by crude oleic acid and selective hydrofining oleic acid respectively were tested.The results showed that the composition of oleic acid had little influence on the physical and chemical properties of TMPTO,but the pour point was increased with saturated fatty acid.The thermal oxidation experiment by the incubator was combined with the acid number and viscosity.The oxidation stability of TMPTO-1 and TMPTO-2 was tested.The results showed that the double bonds in polyunsaturated fatty acids were easily oxidized,which results in the degradation of oxidation stability of TMPTO.So it is still a research emphasis in the future to improve the selectivity of catalyst for catalytic hydrogentation of crude oleic acid.