Characteristics Of Fillers And Its Effect On The Properties Of Thermal Insulation Coatings

The sun brings endless stream of energy to the earth, but simultaneously causesthe interior and exterior surfaces of buildings to quickly overheat, which leads to aseries of problems to peoples’ production and daily life. Utilization of thermalinsulation coatings has shown potential to reduce interior and exterior surfacetemperatures and to reduce peak power loads while improving indoor thermalconditions.This paper presents an experimental study on the influences of thermalinsulation by individually adding different types of pigments and fillers; and acomposite thermal insulation coating with better heat insulation was preparedsuccessfully using appropriate fillers. To solve the problem of poor strength ofhollow glass microspheres (HGM), on one hand, coated hollow microspheres withdifferent coating conditions were prepared; on the other hand, hollow polymermicrosphere was used to replace HGM. The strength, morphologies and thermalinsulation properties of coated HGM were characterized by detector of thermalconductivity, scanning electron microscopy(SEM) and experimental apparatus. It isconclud that:(1) The thermal insulation of coatings were variably increased by addingtitanium dioxide or mica, while the thermal conductivity were gradually increasedwith the increase of adding amount. The adding of titanium dioxide increases theinsulation properties of coating significantly, although its thermal conductivity wasrelatively higher, but the thermal insulation tend not to vary with the addition of bothkinds of fillers.The adding of diatomite or HGM into the coatings, which could lower thethermal conductivity of coatings, increases the heat insulation significantly. With theincrease of the adding amount, the thermal conductivity of coatings was reduced,and the thermal insulation performance was enhanced. Simultaneously, the HGM performed better than the diatomite in the thermal insulation. Two types of HGMswere applied on identical coatings and their performance was compared with eachother. The insulation performance of HGM S (the HGM with an average particle sizeof60um) was relatively better, accordingly the low intensity of HGM was inevitable.The result applied quite the opposite when the average particle size of HGM was40um.(2) The composite coatings were prepared by using diatomite, titanium dioxide,mica, potassium titanate whisker and HGM S as the main fillers. When the amountof potassium titanate whisker was12wt%, of HGM S was8wt%, the mosttemperature difference of coatings was21℃, which was9℃higher than ordinarylatex paint on the market.(3) Both the strength of HGM S and thermal conductivity of coatings wereincreased with different coating conditions. The approach coated with silica-sol, withsilicone resin and with silicone resin/Rutile TiO2shells would weaken the heatinsulation performance gradually. The heat insulation property of HGM has certainenhancement when the weight ratio of HGM/silica-sol/titanium dioxide were3:1:1,by which the strength and thermal insulation property of HGM were the best, whichwas0.5℃higher than the uncoated HGM.(4) Replacing HGM S with hollow polymer, when adding6wt%hollow polymermicrosphers, the coating exhibited the same heat insulation performance as the8wt%HGM-added sample.