Study On The Synthesis And Application Of Polymethacrylate Pour Point Depressant

As a kind of important lubricant additives, pour point depressant(PPD) can effectively improved the low temperature fluidity of the lubricant. The pour point of the lubricant will be reduced by the PPD. So the using performance in low temperature of the lubricant enhanced. The main content of this paper is the synthesis of the binary copolymer poly methyl acrylic acid high carbon ester-styrene(PMV) and the terpolymer poly methyl acrylic acid high carbon ester-styrene-vinyl acetate (PMVA). First, methyl acrylic acid high carbon ester is prepared by esterification reaction. The synthesis of hexadecanol methylacrylate is taken as an example. The highest yield of esterification reaction conditions are obtained by single factor experiment and five factors four levels orthogonal experiment method. The best reaction conditions are acid alcohol ratio 1.2:1, the reaction temperature 130"C, reaction time 6h, dosage of catalyst and polymerization retarder 1.2% and 0.6%(the percentage of total mass of reactants). Then the synthesis of the terpolymer PMVA16 is taken as an example. The best polymerization condition is got by single factor experiment, Plackett-Burman and Box-Behnken experimental design. The optimal synthesis conditions are monomer ratio n(meth hexadecyl acrylate):n(styrene):n(vinyl acetate)=2.1:1:1, the reaction temperature 85℃, the reaction time 6.1h and the amount of initiator 0.9%.The prepared PPD is added into different base oil to measure its effect on different oil. The results show that the PMV effect on intermediate base oil is best. The pour degree ASP of PMV18 is the highest, under certain conditions, which can reach 8.2℃. The PMVA effect on paraffinic base oil is best.The pour degree of PMVA18 is the highest,under certain conditions, which can reach 9.9℃. For the PMV18 and PMVA18, the best additive condition are that the amount of them is respectively 0.8% and 1.0%, and the additive temperature all is 60℃. The sensitivity of Naphthenic base oil for PMV and PMVA is poor, so the PPD effect of these two kinds polymer for naphthenic base oil is not significant. Finally, the micrograph of paraffinic base oil without and with PMVA18 is analyzed for the mechanism of pour point depressant. Concluded that the mechanism of PPD is the result of adsorption theory, eutectic theory, nucleation theory and wax solubility theory combined action.