Research On Preparation And Performance Of Aerogel Thermal Insulation Composite

In this paper,TEOS was used as the silicon source to prepare SiO₂ aerogel sol,and the expanded perlite/asbestos wire fiber was loaded into the SiO₂ aerogel sol,then the gel was aged,and finally the expanded perlite/asbestos wire fiber SiO₂ aerogel thermal insulation composite materials were prepared by atmospheric pressure drying method.In this experiment,the effects of gel time,amount of expanded perlite,and amount of asbestos fiber on the performance of the composite were studied,and the morphology and structure of composites were characterized by means of SEM and FT-IR.The experimental results show that when the gel time is 20 minutes,the added amount of expanded perlite is 1.5 g and the added amount of asbestos fiber is 5 g,each characterization proves that the aerogel thermal insulation composite material has the best performance,the density is 614 kg/m³,and doesn't change the structure of the aerogel itself.The thermal conductivity of the expanded perlite/asbestos fiber SiO₂ aerogel composite is 0.1673 W/?m·K?and the thermal diffusion coefficient is 0.2946 mm²/s.In this article,the physical additive method and chemical additive method were also used to prepare and study the polyurethane rigid foam and SiO₂ aerogel composite materials.Polyurethane rigid foam is a kind of polyurethane,which is usually a foamy solid produced by mixing and stirring polyhydric alcohol and isocyanate.The physical addition method is to use TEOS as the silicon source,absolute ethanol as the solvent,hydrochloric acid as the acid catalyst,ammonia as the alkali catalyst,and asbestos fiber to reinforce the SiO₂ aerogel.The ground foam is ground into powder as a modified material and added to the gel,and then aged with ethanol,and finally the SiO₂ aerogel thermal insulation composite material is prepared by the atmospheric drying method.The chemical addition method uses a mixture of polyether polyol,triethanolamine,and water as material A,and isocyanate as material B.A certain amount of TEOS,absolute ethanol,and 0.1%acetic acid are stirred at 50°C for 90 minutes,The solution is used as material C.First,material A and material C are mixed at a certain ratio,and then they are mixed with material B at a mass of 1:1 to form a modified polyurethane foam,thereby they prepare polyurethane rigid foam and SiO₂ aerogel insulation composite materials,and perform a series of characterization and performance tests on composite materials.Through the analysis of the test results,when the density of the composite material is 34.14 kg/m³,the toughness is the strongest,the tensile stress is 840 kPa,and the minimum thermal conductivity is 0.03454 W/?m·K?.