The Preparation Of Thermal Insulation Coating And The Effect Of Pigment And Filler Gradation

Thermal insulation coating (TIC) can effectively decrease the surface temperature of buildings and storage facilities to prevent the internal temperature rise, which cuts back the utilization of refrigeration equipment to reduce energy consumption. Owing to the gradation of pigments and fillers, TIC possesses advantages on the construction process and insulation effect. However, the effect of particle size, distribution and gradation of pigments and fillers on the properties of TIC is seldom addressed and the mechanism remains ambiguous, which results in an impact on the insulation effect and cost of TIC and finally limits the development. Thus, considering the properties and cost, study on the effect of pigments and fillers gradation on the properties of TIC is of great significance.In this thesis, the preparation of TIC and the gradation of fillers and pigments were studied based on the research status and problems remained. The influences of TiO2 pigment gradation and shell powder filler on the properties of TIC were systematically studied and the mechanism was analyzed. Main research results are as follows:Graded TiO2 as pigments, hollow glass spheres and talcum as fillers, acrylic emulsion as resin were selected to prepare a high performance TIC. The thermal properties and mechanical properties were tested and the effects of TiO2 gradation on the properties of TIC were evaluated. The solar reflectance and the thermal insulation were found to increase with the content of nano-sized TiO2. The mechanical properties such as the wash resistance and film adhesion were found to increase with the incorporation of nano-sized TiO2. Such improvement in the properties of the coatings was attributed to the increased specific surfaces and the lower thermal conductivity of nano-sized TiO2.Natural shell powder as fillers, TiO2 as pigments, fluorocarbon emulsion as resin were selected to prepare a high performance and low cost TIC. Solar reflectance, thermal insulation performance, film adhesion and wash resistance were tested and the influence of shell powder with different particle sizes on the performance of TIC was compared with calcium carbonate. Experimental results showed that TIC with smaller shell powder performed higher solar reflectance, superior thermal insulation effect, lower thermal diffusivity, better wash resistance and film adhesion strength. It was attributed to a denser coating surface, which increased the reflectance to light and heat, with the decrease of particle size of shell powder.The experimental results obtained herein demonstrated that, due to the boundary scattering effect and phonon confinement effect, smaller particle size of pigments and fillers results in more interfaces in coating, and thus enhanced scattering efficiency of light and the thermal resistance, which consequently improves the thermal insulation performance of coating.