Enhancement on thermal, electrical and waterproof performances of cellulose insulating paper with Ar/OMCTS/BN plasma

Cellulose paper plays the key role in the oil-paper insulation system ensuring safe and reliable operation of power systems, which faces challenges related to its inherent low thermal conductivity, high dielectric constant and hydrophilicity. Herein, polymerization reactions are induced on the surface and within the bulk of the cellulose insulating paper via atmospheric-pressure low-temperature plasma with a precursor formed by incorporating BN powders into octamethylcyclotetrasiloxane (OMCTS). As indicated by SEM, EDS, FTIR, and XPS results, a low-polarity cross-linking network is constructed within intrinsic porous structures of the paper, comprehensively improving thermal, electrical and waterproof performances. The thermal conductivity is increased by 15.9%, thereby enabling a significant enhancement in the heat dissipation capability. The relative dielectric constant of the insulating paper is decreased by 27.3%, maintaining effective dielectric adaptation with insulating oil. The surface and bulk insulation performance of the oil-impregnated paper is reinforced, with a 9.4% increase in the flashover voltage and a 17.5% improvement in bulk breakdown strength. The wetting property is changed from hydrophilic to hydrophobic, reducing water absorption by 32.6%, inhibiting the transport of water molecules. This work provides a promising approach for developing high-performance insulating paper for safe and stable power transmission.