Study On Synthesis And Properties Of Transparent Insulation Waterborne Polyurethane Modified By Nano-ATO

Both ultraviolet light and infrared lighthave a strong energy,which is similar to the energy involved in chemical reactions,these two kinds of light have strong damage to the all materials exposed in the sun,especially to polymer material.To solve the above problem,there is a requirement to modify the materials.The introduction of nano-metal oxide into the polymer,developing a series of inorganic-organic composite materials which can block ultraviolet radiation,blue light and NIR-ray so as to achieve the purpose of transparent insulation,preparing optical films,is the development of transparent insulation coating important development direction.This method is not only environmentally friendly,but also has a simple process,low cost and other excellent features.Environmentally friendly waterborne polyurethane?WPU?has excellent properties such as molecular structure can be designed,excellent abrasion resistance,strong adhesion,low temperature flexibility,lowflammable volatile organic compounds and so on.It is widely used in textile,leather,adhesives,coatings and other industries,it is the first choice for the preparation of transparent insulation materials.The particle size of the nanoparticles is much smaller than that of the visible light,which makes the nanocomposites have high transparency.The n-type semiconductor materials such as nano tin oxide are the conductive oxides,and the band gap is basically more than 3eV,They have a good absorption of ultraviolet light,reflective infrared light,it is the first choice for the preparation of transparent insulation materials.However,the compatibility problem between inorganic particles and organic particles is a key problem in the preparation of transparent heat-insulating coatings.Silane coupling agents are silane with organic functional groups,which have the ability to chemically combine with organic and inorganic materials in their molecular structures of the reactive groups.In this project,the problem of dispersibility of inorganic particles in the substrate is improved by silane coupling agent.In this paper,polyurethane prepolymer was prepared by acetone method,both siloxan and inorganic nano-tin oxide antimony?ATO?particles were used to modify the WPU,preparing a composite material with heat insulating and transparency.In the first part,isophoronediisocyanate?IPDI?,polytetrahydrofuran?PTMEG2000?were used as the main reaction monomer,2,2-hydroxymethyl propionic acid?DMPA?was used as thehydrophilicchainextender,polyurethaneprepolymerwasprepared,and3-aminopropyltriethoxysilane?AMEO?was incorporate into the system,the Si-O bond with larger bond can be introduced into the system by the reaction between-NH₂and-NCO,a series of?Si-WPU?were prepared with different content of AEMO.The structure and properties of the polymer were analyzed by tensile testing machine,Fourier transform infrared spectroscopy,thermogravimetric analyzer and contact angle tester.The results show that the tensile strength of the waterborne polyurethane is improved,the elongation at break is reduced,and it has a high thermal stability,good hydrophobic properties and excellent water resistance.In the second part,in situ polymerization was carried out by using AMEO modified aqueous polyurethane as a template,and ATO was introduced.The Si-OH was introduced into the prepolymer end groups by hydrolysis condensation with 3 ethoxy end groups of AMEO,and reacted with the hydroxyl groups on the surface of ATO particles,which made the ATOdisperse well.X-ray photoelectron spectroscopy?XPS?,transmission electron microscopy,ultraviolet spectroscopy,blackboard thermometer and other instruments were used to analyze the structure and properties of waterborne polyurethane modified by ATO.The structure shows that AMEO can significantly improve the dispersibility and stability of ATO in the polymer.The good dispersibility of ATOimproved the transmittance in the visible region and the shielding ability of the near infrared.