Fabrication Of Thermal Insulation Hollow Spheres And Their Application In Polyacrylate

Polyacrylate had been paid more attention owing to its economics and good film-forming properties.However,the thermal insulation performance of pure polyacrylate is not outstanding.The hollow TiO₂ spheres and double-shell hollow SiO₂@TiO₂ spheres,which have bigger specific surface area,high reflection of light,cavity structure and other outstanding properties are widely used in a lot of field.Nonetheless,hollow TiO₂ spheres and double-shell hollow SiO₂@TiO₂ spheres are used to enhance the thermal insulation properties of glass coating are no reported.In this paper,hollow TiO₂ spheres were synthesized by template free method and template method,meanwhile the double-shell hollow S iO₂@TiO₂spheres were synthesized by template method.The effects of reaction conditions on the morphology of three kinds of hollow spheres were investigated.And then these hollow microspheres were introduced into polyacrylate emuls ion by physical blending approach to prepare three kinds of corresponding composite emuls ions.The preparation conditions of hollow spheres were optimized with thermal insulation properties,light reflection performance,UV-shielding performance,and mechanical properties of composite films as indexes.Based on above researches,the main contents are listed as follows.Hollow TiO₂ spheres were eas ily fabricated through a template-free solvothermal route.The diameter of hollow TiO₂ spheres was 1μm.The shell of hollow TiO₂ spheres possessed mesoporous structure.When the raw material was tetrabutyl titanate（TBT）,the amount of TBT was 0.5 g,the reaction time was 5 h,the reaction temperature was 220℃,the content of the hollow TiO₂spheres was 3%.The performance of corresponding polyacrylate/hollow TiO₂composite films were optimal.Compared with pure polyacrtylate film,the thermal conductivity,the ultraviolet transmittance of composite films decreased by 17.32%,52.14%,respectively,and the light reflectivity,the tensile strength and elongation at break of composite films increased by 580.51%,13.03%,17.79%,respectively.Hollow TiO₂ spheres were easily fabricated through a template method.The diameter of hollow TiO₂ spheres could be controlled form 40³50 nm.When the raw material was tetrabutyl titanate（TBT）,the amount of triethanolamine was 2mmol,the dosage of ammonia was 272 mmol,the reaction temperature was80℃,the reaction time was 8 h,and the content of the hollow TiO₂ spheres was2%.The performance of corresponding polyacrylate/hollow TiO₂ composite films were optimal.Compared with pure polyacrtylate film,the thermal conductivity and the ultraviolet transmittance of composite films decreased by25.83%and 61.37%,the light reflectivity,tensile strength and elongation at break of composite films increased by 587.51%,70.43%,135.10%,respectively.Double-shell hollow SiO₂@TiO₂ spheres were eas ily fabricated through a template method.The diameter of double-shell hollow SiO₂@TiO₂ spheres could be controlled form 70⁴20 nm.The shell of hollow SiO₂@TiO₂ spheres possessed mesoporous structure.When the amount of silicon source was 3%,the diameter of PS spheres were 300 nm,and the content of the hollow SiO₂@TiO₂spheres was 3%.The performance of corresponding polyacrylate/double-shell hollow SiO₂@TiO₂ composite films were optimal.Compared with pure polyacrtylate film,the thermal conductivity and the ultraviolet transmittance of composite films decreased by 32.74%and 98.15%,the light reflectivity,the tensile strength and elongation at break of composite films increased by 771.40%,38.30%,17.96%,respectively.The comprehensive performances of three composite emuls ions and their application in glass finishing were that polyacrylate/double-shell hollow SiO₂@TiO₂ composite emuls ion is the best,while polyacrylate/hollow TiO₂composite emuls ion with that the hollow TiO₂ spheres were made by the template-free method is the worst.