KH560-SiO2/PI Insulating Paper Preparation and Characterisation

Heat-resistant insulating paper has a very important application in the field of motor slot insulation and heat-resistant transformer manufacturing. With the development of new energy sources such as wind power, highspeed rail, and new energy vehicles, higher requirements are placed on the thermal stability and electrical strength of insulating paper. Polyimide (PI) fibers have excellent properties such as insulation, heat resistance, and mechanical strength. In this paper, polyimide insulating paper was prepared by electrospinning, and doped with nano-Sio 2 modified by silane coupling agent KH560. Through the surface potential decay test, it is found that the doping of insulating paper after modification can introduce more deep traps into the insulating paper of PI matrix. When the optimal addition amount of KH560-Sio 2 is 3 wt%, the breakdown field strength of KH560-Sio 2 /PI composite insulating paper can reach up to 76. SkV/mm, the lowest dielectric constant is 1.81, and the dielectric loss is $1.13\times 10^{-3}$, so the longitudinal tensile strength can reach 258.95 MPa. The research results not only provide theoretical support for the design of insulation structures, but also provide new materials and new ideas for the development of new heat-resistant transformers and motors, and also have potential application value.