This invention discloses a method for preparing a novel ultra-
high voltage high-performance composite insulating material, belonging to the field of composite insulating material preparation technology. The technical solution includes the following steps: S1, preparing a modified
epoxy-
silicone rubber composite
resin matrix: 40-50 parts by weight of
bisphenol A type
epoxy resin (E-51) are placed in a reaction vessel, heated to 60-70℃, and continuously stirred at a stirring rate of 300-500 r / min. 10-15 parts by weight of terminal hydroxyl polysiloxane (molecular weight 5000-10000) are added, and the temperature is kept constant for 1.5-2 hours; subsequently, the
system temperature is lowered to 40-50℃. The beneficial effects of this invention are: by setting up a
resin matrix system of "terminated hydroxyl polysiloxane modified
epoxy resin + nano-
alumina /
boron nitride composite reinforcement," the problem of imbalance between
high voltage resistance and
aging resistance in existing materials is solved. It exhibits significantly improved
dielectric strength, greatly reduced
dielectric loss, and excellent high and low
temperature cycling performance, meeting the long-life operation requirements of ultra-
high voltage equipment.