The Synthesis Of Two Kinds Of PPD For Lubricant And Study On The Pour Point Depression Mechanism

With the exhaustion of oil resource, the pour point of new exploited oil is becoming higher and higher, which heightens the pour point of lubricant's base oil accordingly, and so the exploration and application of high effect pour point depressants become more and more exigent. Polymeric Fumaric ester and Vinyl Acetate(PFVA) and Polymeric Methylic Acrylate (PMA) are two popular Pour Point Depressants(PPDs), but the synthetic routes are complicated and the costs are high, especially the applied range is narrow. So it's urgent to improve the synthetic technology and to change the composition, in order to get low cost products which can be applied broadly.Firstly, Fumaric esters /FE and methylic acrylates /MA are synthesized by making different high carbon alcohols react with fumarate acid and methacrylic acid respectively when taking toluene as solvent and water carring agent and taking paratoluenesulfonic acid as catalyst. Then the polymer of T818 PPD—PFVA is synthesized by polymizing refined FE and Vinyl Acetate when taking benzoperoxide as ignition agent; The polymer of T602 PPD—PMA is synthesized by the way of uni-step, which is promoted firstly in this thesis. The structures of FE, PFVA and PMA are analyzed by IR spectroscopy; the pour point depressions of PFVA and PMA are tested according to GB510; the pour point depressing mechanism and the factors that influence the effect largely are discussed, and the analysis of base lubrication by gas phase chromatography-mass spectrum union equipment is taken into account.On the basis of large amount of experiments and analysis, the results show that:(1) The carbon count of FE dominates the applied range of PFVA. PFVA/C8 has no effect on both paraffin and naphthene base lubrication but can lower the freezing point largely; PFVA/C12 and PFVA/C14 have good effect on paraffin base lubrication but poor on naphthene base lubrication; PFVA/C16 and PFVA/C18 have good effect on naphthene base lubrication but poor on paraffin base lubrication; the PFVA PPD which has obvious effects on both paraffin and naphthene base lubrication can be synthesized by changing the carbon count of mixed FE.(2) Uni-step technology can save cost and time largely, and meanwhile the products of that have no difference with the products of two step technology; the polymerization degree of PMA has great effect on the applied range while the carbon count of MA almost has no influence. And because the polymerizing temperature dominates the polymerization degree, the PMA PPD which has obvious effects on both paraffin and naphthene base lubrication can be synthesized by changing the polymerizing temperature; the PMAs from mixed MAs have better effects than that from single MA.(3) The mechanism of the two PPDs are both: long chain alkyl co-crystallize with the wax of lubricants and then be the nucleus of the coming crystal, and that makes the crystal cannot combine into net structure, and so the low temperature fluidity is improved; the wax carbon amount, wax structure, wax molecular weight and the viscosity of fuel and the length of alkyl side chain, polarity group and the molecular weight of the polymers are all have influence on the pour point depression.