Preparation And Properties Of Polyimide - Inorganic Hybrid Energy-saving Glass Film

The energy saving reconstruction of existing buildings is an important measure in our country. In which energy-saving films were pated on the window glasses. In developed countries, the popularization rate of energy-saving films is more than 75%. However, the films are only used in Beijing, Shanghai, Guangzhou and other major cities in our nation, as well as the market is monopolized by the foreign brands, such as the United states 3M, CPF (Long membrane) and other monopolistic brands. In this dissertation, the author aims to develop an organic-inorganic hybrid materials with independent intellectual property. With a view to the application of this hybrid materials in the film posting field, playing an important role in energy conservation.In this dissertation, the polyimide materials was selected for the organic main phase of the films, owing to its excellent optical properties and thermal stability properties. The hybrid sol was prepared by doping inorganic components such as SiO2, ZnO, Al2O3 to the organic phases. After the thermal imidization, the polyimide/SiO2, polyimide/ZnO, polyimide/Al2O3 were obtained. As a standard of uv-visible light transmittance, SiO2 was chosen as the optimal inorganic phase dopants. The effect of PAA sol viscosity factors include reaction temperature, monomer molar ratio and aging time.The viscosity of best coating quality was at the range of 85～122mPa·s, and the sol systems was stabilized after aging 24h.The effect of the light transmission rate factors were:the addition amount of SiO2, monomer molar ratio and the addition amount of coupling agent. The optimization process of PI/SiO2 hybrid films preparation was:the addition amount of SiO2 5%, the monomer molar ratio (ODA:PMDA) 0.95:1, coupling agent addition amount 1:25.The analysis for the transmittance of PI/SiO2 hybrid films, insulation, thermal stability, microstructure and structural showed that:the average light transmission rate of PI/SiO2 hybrid films in the visible district and ultraviolet district, was 85.6% and 12.9%.Compared with the darkroom without coating glass, the temperature of darkroom whose glass coated PI/SiO2 hybrid films was lower 3.5℃. According to technique of GB/T2680-94,as an example of a building whose window-wall ratio was 0.22, pasted films, its shading coefficient and total heat transfer coefficient decreased. The incoming heat was reduced from 34.67w/m2 to 23.60 w/m2.The thermal stability of PI was improved after doped SiO2, compared with PI, the PI/SiO2 temperature of loss 5% weight raised from 520℃to 544℃.The inorganic phase uniformly dispersed in the organic phase, two phases are linked closely. Preliminary analysis showed that:Imide ring structure was formed by thermal imidization treatment, the coupling agentγ-aminopropyl triethoxysilane connection between the inorganic phase and organic phase by hydrogen bond structure.