十六硫醇作用下绝缘纸老化降解的反应分子动力学模拟

Molecular Dynamics Simulation of Aging Degradation of Insulating Paper Under the Effect of Hexadecanethiol

变压器绝缘油中的十六硫醇会加速纤维素绝缘纸的老化,揭示油中十六硫醇对纤维素老化的微观作用机理对于优化绝缘纸的抗硫腐蚀措施具有重要价值。然而,目前关于十六硫醇对绝缘纸老化降解影响的研究主要聚焦于实验手段,其微观作用机理尚不清晰。鉴于此,采用反应分子动力学模拟方法,初步研究了十六硫醇对纤维素绝缘纸老化的微观作用机理。模拟结果表明:随着十六硫醇浓度增加,十六硫醇分子热解产生的自由基数量增加,这些自由基易与纤维二糖分子发生反应,其攻击纤维二糖分子的主要路径有4种。通过对比研究发现,纤维二糖分子的仲羟基与自由基反应所需能量最低,使得纤维二糖分子的仲羟基成为自由基攻击的主要对象。上述结论从分子水平初步揭示了十六硫醇加速绝缘纸老化的微观作用机理,这有望为优化绝缘纸的抗硫腐蚀措施提供一定的理论依据。

The aging of cellulose insulating paper can be accelerated by hexadecanethiol contained in transformer oil.It is valuable to reveal the microscopic mechanism of hexadecanethiol on cellulose aging to optimize sulfide-resistant measures for insulating paper.However,most of the existing studies about the effects of the hexadecanethiol on the aging of insulating paper mainly focus on experimental methods,and the microscopic mechanism is not clear.Therefore,the simulation method of reactive molecular dynamics was used to preliminarily study the microscopic mechanism of hexadecanethiol on the aging of insulating paper.The results show that,with the increase of hexadecanethiol concentration,the number of free radicals produced by the pyrolysis of hexadecanethiol will increase,which are easy to react with cellobiose molecules.These radicals attack cellobiose molecules in four main paths.Through comparative studies,it can be found that the secondary hydroxyls of cellobiose molecules are the main target of free radical because of their low energy required for the reaction.This conclusion preliminarily reveals the microscopic mechanism of hexadecanethiol accelerating the aging of insulating paper at the molecular level,which is expected to provide a certain theoretical basis for the optimization of the sulfide-resistant measures for insulating paper.