Preparation And Properties Study Of High Inorganic-organic Ratio Composite Emulsion

High inorganic-organic ratio high SiO₂ content polyacrylate / silica sol composite emulsion was synthesized through in-site emulsion polymerization. The influence of the inorganic-organic ratio on emulsion stability, emulsion film hardness, emulsion film water-resistance was studied. The microstructure of the composite particle was characterized through FTIR, TEM, DLS, DSC, TGA. The application of the composite emulsion on latex paint was made. The main study is as follows.1. The influence of a serials of inorganic-organic ratio on composite emulsion and composite emulsion film was studied. The result shows that the stability of the emulsion goes down as the inorganic-organic ratio rises and the stability to the calcium is on the contrary. The hardness and the water resistance of the film go up with the inorganic-organic ratio. Taking several factors into consideration, the inorganic-organic ratio should be under 0.900.2. The structure of composite emulsion particles were characterized through Transmission Electron Microscope(TEM), Fourier Transform Infrared(FTIR). It was shown that the particle of the composite emulsion contains two kinds of core-shell structure. Chemical bonds between the core and the shell were confirmed by FTIR test. There is dissociated SiO₂ in the emulsion. SiO₂ particles dispersed uniformly in composite emulsion. The size of the composite emulsion particles was 84～86nm.3. DSC shows that the Tg of composite emulsion decreases compared with that of blend film. 4. The test of composite latex paint shows that composite emulsion is superior to the normal latex paint on the aspect of stain resistance. The potential value needs more exploration.