Preparation Of Waterborne Thermal Insulation Coatings And Study On Their Thermal Insulation Properties

With the development of science and technology,economy and society,the energy-saving and environmentally-friendly materials have been paid more and more attention.In order to improve the energy-saving efficiency of architectural glassy materials,more and more researchers involved in the study on the waterborne transparent heat-insulating coatings.The organosiloxane(KH570)modified acrylic emulsion with Ketone-Hydrazide cross-linking at room temperature was prepared after the component and process optimization,and then further mixed with silane coupling agent KH560 to prepare the waterborne transparent heat-insulating coating.The influence of the organosiloxanes(KH570 and KH560)on the emulsion properties and the performance of the coating including the thermal insulation were systematically studied.In this work,the specific innovations are as follows:(1)The waterborne transparent heat-insulating coating was prepared by combining the multi-crosslinking of KH560 and ketone-ruthenium,and the introducing the Si-O-Si highly cross-linking networks,thus reducing the heat transfer coefficient and the transmittance of ultraviolet light and infrared light of the heat-insulating coating,resulted in the excellent heat-insulating efficiency.(2)The two involved heat insulation mechanisms of barrier and reflection generated by the incorporated organosiloxane was proposed.The main research contents of the thesis are as follows:(1)According to the performance requirements of the waterborne transparent heat-insulating coating,the formula of organosiloxane modified acyclic emulsion was designed and the process conditions of emulsion copolymerization was optimized to prepare the silicone-modified ketone-ruthenium crosslinked acyclic emulsion.The structure and morphology of the silicone modified ketone-ruthenium crosslinked acyclic emulsion and waterborne transparent heat-insulating coating were determined by FT-IR,TEM and SEM.(2)The structure of waterborne silicone modified ketone-ruthenium crosslinked emulsion and waterborne transparent thermal insulation coating film was characterized by FT-IR,DSC and TGA.TEM and SEM demonstrated the spatial network structure was formed by mutual crosslinking of the film formations.The excellent heat insulation effect of the waterborne transparent thermal insulation coating film was revealed by measuring the thermal conductivity efficiency.(3)The effect of the addition amount of silicone KH570 on the monomers conversion rate,gel fraction,and their emulsion particle size was investigated.The optimum formula of silicone modified ketone-ruthenium crosslinked acrylic emulsion was obtained,namely,the optimum addition amount of silicone KH570 was 11.46%(formulation PA6),the emulsion gel fraction was 0.27%,and the conversion rate was 96.22%.The emulsion has an average particle diameter of 100 nm.FT-IR demonstrated that the silicone KH570 and the acrylate monomers formed a chemical bond by a double bond radical reaction.Additionally TEM showed that the emulsion film formation process was cross-linked and it had a spherical core-shell structure.(4)The thermal insulation properties of the waterborne transparent heat-insulating coatings were investigated.The optimal formulation of the waterborne transparent heatinsulating coating was determined,that is,the weight percentage of KH560 to the silicone modified emulsion was 25.62%(formulation P7),and the degree of crosslinking of the paint film was reached to 54.3%,as for the overall performance of the paint film: adhesion level 0,ethanol resistance 100 times,water immersion 36 h,hardness 3H,5% HCl aqueous solution corrosion resistance 20 h,5% NaOH corrosion resistance 24 h,friction resistance 40 times.The results of the FT-IR,DSC and TGA also proved that the reactions of epoxy and amide groups,ketone-oxime and silane coupling agent hydrolysis occured between KH560 and silicone modified ketoneruthenium cross-linking emulsion during film formation and the silanol condensation reaction occured to form the hydrogen bonding of the silanol groups with the substrate.(5)We also studied the thermal insulation properties of waterborne transparent thermal insulation coatings.By testing its optical transmittance,thermal conductivity,and thermal insulation efficiency.The optimal formulation of the silane coupling agent KH560 and silicone modified emulsion for the waterborne transparent thermal insulation coating film was determined,that is,the weight percentage of KH560 to the silicone modified emulsion was 25.62%(formulation P7),and the visible light transmittance was 77.42%.The infrared transmittance was 56.56%.The ultraviolet transmittance was 66.67%,the thermal conductivity was 0.18w/(mK),and the heat insulation efficiency was 8.94%.Additionally,TEM showed the waterborne transparent heat-insulating coating formed a dense network structure through the crosslinking reaction and the hybridization reaction during the film formation process.SEM also showed the surface of the coating film was smooth and there was a dense layered cross-linking inside.