Polysilsesquioxane-modified Cellulose Insulating Paper with Excellent Mechanical Properties, Electrical Properties and Aging Resistance

Abstract Nano-modified insulating paper is regarded as a promising material in power systems due to its outstanding performance. In this paper, three kinds of polysilsesquioxane nanoparticles with different substituents (octaaminophenyl POSS, octaphenyl POSS, and octamethyl POSS) were used to prepare modified cellulose insulating paper. It was found that the doping of polysilsesquioxane nanoparticles could effectively improve the tensile strength of insulating paper and reduce its relative dielectric constant. Specifically, doping of 10 wt% octaaminophenyl POSS (OAPS) showed the best modification effect. On this basis, accelerated thermal aging test was carried out on the 10 wt% OAPS modified insulating paper. Compared with the unmodified sample, the tensile strength of the modified sample increased by 16.87% and the relative dielectric constant decreased by 24.63% after aging at 130 ℃ for 31 days. Molecular simulation technology was used to study the micro mechanism and results show that OAPS can significantly improve the tensile strength, dielectric properties and thermal stability of cellulose insulating paper by forming hydrogen bonds with cellulose chains, reducing the system polarizability and the movement strength of cellulose chains.