The application discloses an
alumina-coated
aramid core-shell
fiber /
epoxy resin composite medium and a preparation method and application thereof, and belongs to the technical field of
polymer composite media and electrical insulation materials. The application solves the problems of insufficient heat conduction performance of existing
epoxy resin, easy agglomeration of traditional inorganic fillers, weak
interface bonding between
aramid fibers and resin, and difficult balance between heat conduction
performance improvement and breakdown performance maintenance. The application constructs an
alumina coating layer on the surface of
aramid fibers through a precursor deposition-thermal
conversion method, and then is modified by a
coupling agent, and is compounded with an
epoxy resin, a curing agent and an accelerator, and is subjected to vacuum degassing and gradient curing to obtain a high-heat-conduction insulation
epoxy resin composite medium. The application has the advantages of simple preparation process, easily available raw materials and controllable cost, and the obtained composite medium has heat conduction performance, electrical insulation performance and mechanical performance, and can be widely applied to the fields of
electronic packaging,
transformer pouring insulation, high-
voltage insulation components and
new energy motor insulation systems.