The structural differences between commonly used cellulose and aramid insulating papers cause their respective advantages and disadvantages. It is necessary to optimize the multi-level structure and regulate the overall performance of insulating papers. In order to explore the structure-activity relationship between insulating paper multi-level structures and their electrical and mechanical properties

the structures of insulating papers and their influence are analyzed level by level based on molecular dynamics simulation and experiments. The results show that the apparent morphology of insulating papers affects the movement of charge

the contact between fibers

and the degree of hydrogen bond connection in the process of polarization and breakdown. The smaller the pores

the higher their packing density

the lower the relative permittivity

the higher the breakdown strength

and the better the mechanical properties; The mean squared displacement of molecular chain in the crystalline regions of aramid and cellulose is 80.0% and 79.3% lower respectively

and their tensile modulus and shear modulus are 318.6%

342.2% and 18.5%

22.2% higher than those in respective amorphous regions. However

their toughness is 40.6% and 15.3% lower respectively than that of counterparts in amorphous regions. Moreover

the crystalline and amorphous regions also restrict the movement and orderly arrangement of molecular chains in the polarization process. Improving the crystallinity of the insulating paper can reduce the dielectric loss

relative permittivity

and volume resistivity

and improve the rigidity and shear resistance

but this enhancement is detrimental to the toughness. The larger the permanent dipole moment of the polar bond in the microstructure of the insulating paper

the larger its relative permittivity. The research findings can provide guidance and data support for the structure regulation of next-generation high-performance insulating papers.