Molecular Dynamics Study on Kinematic Viscosity of Peanut Oil Methyl Ester

As a renewable and degradable insulating oil, vegetable oil has the disadvantage of high kinematic viscosity. In order to improve the kinematic viscosity of vegetable insulating oil, methylated vegetable oil with low kinematic viscosity was prepared by transesterification. In this paper, the molecular model of peanut oil and peanut oil methyl ester was established, and the molecular dynamics simulation of the oil model was carried out. The micro mechanism of methyl esterification reducing kinematic viscosity was studied from three parameters: mean square displacement, mean square radius of gyration and free volume. The results showed that methylated vegetable oil was produced by transesterification of vegetable oil. The diffusion coefficient and free volume fraction of methylated vegetable oil are larger, and the mean square radius of gyration is smaller. It shows that the shortening of carbon chain makes the molecular chain not easy to entangle, thus reducing the kinematic viscosity of vegetable oil.