# Unveiling the Micro-Mechanism of Functional Group Regulation for Enhanced Dielectric Properties in Novel Natural Ester Insulating Oil TME-C10

## TL;DR

This paper explains how specific molecular structures in a new insulating oil improve its performance and longevity compared to traditional oils.

## Contribution

The study reveals the micro-mechanism of functional group regulation in TME-C10 ester oil using DFT calculations.

## Key findings

- TME-C10 shows improved chemical stability and anti-aging ability by eliminating C=C double bonds and β-H groups.
- TME-C10's electronic behavior is controlled by ester groups, leading to better dielectric properties than GT molecules.
- TME-C10 exhibits n→σ∗ electronic transitions and higher HOMO energy, ionization energy, and electron transition energy than GT.

## Abstract

The functional groups in the molecular structure of natural ester insulating oil have a significant impact on its physicochemical and electrical properties. This article takes the novel synthetic ester TME-C10 and traditional natural ester GT molecules as research objects, and based on density functional theory (DFT) calculations, systematically explores the micro-mechanism of the effects of C=C double bonds, ester groups (-COOC), and β-H groups on the performance of insulating oils. The results show that the chemical stability and anti-aging ability of the TME-C10 molecule are significantly improved by eliminating the C=C double bond and β-H group. The electronic behavior of the TME-C10 molecule is mainly controlled by the ester group (-COOC), while the GT molecule is significantly affected by the unsaturated C=C double bond, resulting in a significant difference in the mode of electronic transition between the two molecules: the TME-C10 molecule shows the n→σ∗ transition, while the GT molecule is the π→π∗ transition. In addition, the HOMO orbital energy level, electron transition energy, and ionization energy of the GT molecules are lower than those of the TME-C10 molecules. Under the action of an external electric field, the TME-C10 molecules exhibit excellent dielectric properties. In summary, the TME-C10 molecules not only overcome the aging defects of traditional natural ester insulating oils, but also possess excellent insulation properties, making it a new type of insulating oil material with broad application prospects.