The invention discloses a preparation method of a diesel oil
pour point depressant. The method includes the following steps of firstly, weighing high alcohols, catalyst,
polymerization inhibitor and
solvent to be sequentially added into a reactor and stirred till solids are completely dissolved, then adding
methacrylic acid, and conducting reduced pressure
distillation, alkali washing and
water washing on the product after reaction ends to obtain methylacrylic acid high-carbon ester; secondly, weighing methylacrylic acid high-carbon ester,
maleic anhydride, initiator and
solvent to be evenly mixed, conducting reacting at a certain
reaction temperature under the protection of
nitrogen, adding
aromatic amine and catalyst after reaction, changing the
reaction temperature for reaction for a certain period of time, conducting reduced pressure
distillation on the reaction liquid after reaction ends, then adding an excessive amount of methyl
alcohol to generate white precipitates, removing supernate, and conducting washing and
vacuum drying on the obtained white precipitates through methyl
alcohol to obtain the diesel oil
pour point depressant. The prepared diesel oil
pour point depressant can remarkably reduce the
condensation point of diesel oil and improve the low-temperature flowability of diesel oil; the raw materials are easy to obtain, the synthesis method is simple, and the additive dosage is small.