Research On Mechanical And Aging Properties Of The Nano-SiO₂/Epoxy Tungmaleic Anhydride Adhesive

Epoxy Tung-maleic Anhydride Adhesive is an important part of high voltage electrical machine main insulation, and it directly affects the stable and safe operation of electrical machine. At the beginning, nano-Silica was treated with silane coupling agent. Nano-Silica with the content of 1 wt%, 2 wt%, 3 wt% and 4 wt%were added into Epoxy Tung-maleic Anhydride Adhesive respectively with ultrasonic method to improve the mechanical and aging properties of the composite,and the flexural strength, impact strength, breakdown strength and permittivity of the composite were measured before and after the thermal aging and electrical aging according to main insulation working conditions.Scanning electron microscopy SEM image shows that treatment described in this paper could make the composite with good dispersion. The mechanical property increased with the addition of nano-Silica before the thermal aging. Flexural strength of 1 wt% loading nano-Silica composite increased by 24.79% and reached to a maximum. Impact strength of 2 wt% loading nano-Silica composite increased by47.11% and reached to a maximum. With the increase of nano-Silica, breakdown strength of the composite increased. 2 wt% loading nano-Silica composite increased by 7.3% and reached to a maximum while the breakdown strength of the composite with 3 wt% and 4 wt% loading were lower than that of the unfilled Adhesive.Permittivity of the composite decreased with the increase of nano-Silica, and 1 wt%loading nano-Silica composite has the lowest permittivity.The breakdown strength of 1 wt% and 2 wt% nano-Silica composite were higher than that of the unfilled Adhesive at the early period of 180 oC thermal aging and trend to the same at the end of 28 days thermal aging.The breakdown strength of unfilled Adhesive and 1 wt%, 2 wt% nano-Silica composite have a certain proportion during 5kV/mm electrical aging process, and 2wt% nano-Silica composite has the best breakdown strength at the end of 20 days electrical aging.To sum up, addition of appropriate nano-Silica could improve the mechanical and aging properties of the Epoxy Tung-maleic Anhydride Adhesive.