Abstract:

A lightweight, environmentally-friendly thermal insulation coating was experimentally applied to the carbon fiber to reinforce epoxy resin composites. The coating is mainly composed of bonding layer, barrier layer and reflective layer, and prepared by using titanium dioxide, silica, aluminum oxide and hollow glass microspheres as function fillers. The addition of waterborne polyurethane with a thermal expansion coefficient of 120×10 ^-6 K ^-1 as a film-forming material, is to solve the problem of cracking caused by the mismatch of the thermal expansion coefficients of the coating and the substrate material. The results show that after being applied the coating, can solidify within 24 h at room temperature. When the thicknesses of the bonding layer, the heat barrier layer and the reflective layer were 80, 120, and 90 μm, the thermal insulation coating has the best performance with reflectance of the coating higher than 0.95, the thermal conductivity at 0.048 W·m ^-1·K ^-1 and the temperature difference as high as 20.1 ℃. After being subjected to thermal shock at 190 ℃ for 6 times, and the maximum weight loss rate of the coating was 3.7%, indicating the coating highly stable. When kept at 160 ℃ for 4 h, its surface turned yellow without falling off, and its nano filler particles still remained stable.

Key words: thermal insulation coating, titanium dioxide, hollow glass microspheres, carbon fiber reinforced epoxy resin composites