In order to study the influence of micro-filler surface modification on the properties of epoxy compositesand UHV basin insulator

surface nano-modified micro-nano alumina filler with different particle size increase values was prepared by the surface grafting of silane method. Epoxy/alumina composites and UHV basin insulator were prepared by blending different proportions of micro-nano alumina fillers to determine their mechanical properties

electrical properties and thermal properties

and compared with unblend epoxy compositesand UHV basin insulator. The results showed that the thermal and electric properties of epoxy composites and UHV basin insulator remained constant after blending carboxylic acid surface grafted alumina filler. however

mechanical properties increased obviously. the tensile strength of epoxy composites increased by 16.5%

the failure pressure value of UHV basin insulator increased by15% when the alumina mass fraction was 15%. With the increase of alumina particle size increased

the electric strength decreased. Alumina surface grafting has practical significance for improving the mechanical properties of epoxy composites and improving the reliability of UHV basin insulator.