The invention discloses a preparation method of modified
vegetable oil. The method comprises the following steps: 1) modifying
vegetable oil with methyl
hydrogen-containing
silicone oil: adding methylhydrogen-containing
silicone oil into a flask provided with a constant-temperature feeding funnel and a condensation
pipe, replacing air in the flask with
nitrogen or
inert gas, opening condensate water, adding a catalyst,
vegetable oil and isopropanol, stirring, heating to 80-85 DEG C, keeping the temperature for 6-7 hours, and performing reduced pressure
distillation to remove low-volatility substances, thereby obtaining
hydrogen-containing
silicone oil modified vegetable oil; and 2) ester exchange: adding methyl
hydrogen-containing
silicone oil modified vegetable oil prepared in the step 1) and (2R,3S)-2,3,4-trihydroxyl-3-methylbutyl dihydrogen
phosphate into an
organic solvent, heating to 95-105 DEG C within 30-40 minutes under a
vacuum pressure of 200 mbar; making the mixture carry out reactions for 2-3 hours under stirring at a stirring speed of 800-1000 rpm, and then carrying out rotary
evaporation at 50-60 DEG C to remove low-volatility substances. The lubricating oil preparedfrom the modified vegetable oil is good in
chemical stability, has an extreme pressure anti-wear effect, does not need to be added with an extreme pressure anti-wear agent additionally, is economicaland environment-friendly, and avoids the problem of overlarge
viscosity caused by using a large amount of auxiliaries.