Analysis of physical and chemical properties of insulation paperboard during thermal aging based on molecular simulation

摘要

In order to understand the degradation mechanism of thermal aging process of insulation paperboard from the microscopic level. In this paper, molecular simulation method was used to construct the cellulose model of insulation paperboard, and different temperatures were applied to study the change process of microscopic performance indicators. The results showed that the increase of temperature will lead to the increase of the mean square displacement of molecules, accelerate the movement of molecules, increase the internal kinetic energy and potential energy of molecules, and reduce the number of hydrogen bonds and other forms of non-bonding interaction energy such as van der Waals force, thereby leading to the instability of intermolecular chemical bonds and accelerating the decomposition of cellulose. Moreover, compared with pure cellulose, the mean square displacement of cellulose in oil is larger and the number of hydrogen bonds is less, which indicates that the increase of temperature in oil will make the molecular movement more intense and easier to crack. With the increase of temperature, the shear modulus and Young's modulus of cellulose model decrease, while the Cauchy pressure increases, which indicates that the increase of temperature will increase the ductility of insulating paper, but reduce its rigidity and weaken its deformation resistance. In this paper, the effect of temperature rise on the physical and chemical properties of pressboard is explained from the microscopic point of view.