The Synthesis and Characterization of Methacrylic Acid Ester-maleic Anhydride Copolymer as a Lube Oil Pour Point Depressant

摘要

The authors synthesized methacrylic acid ester (AE) monomers by direct esterification of methacrylic acid and fatty alcohols using paratoluenesulfonic acid as catalyst, hydroquinone as polymerization inhibitor, and toluene as solvent. Then, methacrylic acid ester-maleic anhydride (AM) copolymers were prepared by solution free radical copolymerization with benzoyl peroxide as initiator. The structures of the monomer and copolymer were confirmed by IR. Differential scanning calorimetry (DSC) was selected as the research method to investigate the wax formation process in the lube oils without and with adding AM. The results show that it possess the best solidification point depression (ASP) when the molar ratio of the reaction materials is 3:1 and the polydispersity is 1.81. It can execute a maximum depression of solidification point (SP) of the tested lube oils by 29, 21, and 20°C, respectively. The AM additive has little effect on the total amount of wax, but just shift the precipitation toward lower temperature.