Vegetable insulating oil is an environmentally friendly liquid dielectric with a high flash point

easy degradability

and renewability. In comparison to mineral insulating oil

plant-based insulating oil exhibits higher dielectric loss factor

poorer low-temperature fluidity

and lower oxidation resistance

leading to a sharp increase in failure rates of vegetable insulating oil transformer. Therefore

the development of plant-based insulating oil with high flash point

low dielectric loss

and strong oxidation resistance is of critical academic significance and engineering value for its application in high-voltage

large-capacity power transformers. We utilized a low dielectric loss plant-oil-base compound

different proportions of highly antioxidative functional groups

and β-H-free trimethylolpropane to synthesize antioxidant palm oil-based polyol esters through ester exchange. Furthermore

we optimized the high-yield synthesis method for insulating oil with high impedance antioxidative functional group grafting onto palm oil-based polyol esters. In addition

the investigation delved into the impact of antioxidative functional group grafting content on the dielectric and antioxidative properties of the oil

and determined the optimal antioxidative functional group grafting content. The results demonstrate that antioxidative functional groups significantly enhance the antioxidative performance of palm oil-based polyol esters with minimal influence on the oil's dielectric properties. An oil with a grafting rate of 1% mass fraction achieves an initial oxidation temperature of 301.9 ℃ and a dielectric loss of only 0.47%. Finally

an antioxidant palm oil-based polyol ester insulation oil with excellent physical

chemical

and dielectric properties was obtained.