Preartion And Properties Of Porous Nitrogen-Bearing Polymer Materials For CO₂ Capture

With the further development of industrialization, the increasing amount of CO₂ is more obvious to lead to the green-house effect. In order to control the content of CO₂ in air, it is particularly important to CO₂ capture or adsorption. At present, the most effective adsorption method is solid adsorption method, in which the porous solid amine-containing materials are widely used. In this thesis, porous nitrogen-bearing polymer materials were prepared by concentrated emulsion template method, and could be directly applied in CO₂ capture. Such material exhibits a better thermal stability and regenerated properties.Firstly, the key point of concentrated emulsion template is keeping the concentrated emulsion stable in the polymerization. In order to increase the stability of the concentrated emulsion, the per-polymerization process is used to increase the viscosity of the continuous phase. The factors in the pre-polymerization process are strictly controlled and their effects on the stability of the concentrated emulsion are investigated, including the per-polymerization temperature, time and the performed system pH value. The structures of the pre-polymer are characterized by the precipitation ratio, FTIR,1H-NMR and viscosity test. The results showed that when the melamine and formaldehyde are used as raw material, the pre-polymerization temperature was 75?, the time was 20 minutes, and the pH value was 8, the viscosity of the obtained pre-polymer is the maximum and the stable concentrated emulsion could be achieved.The pre-polymer is used as the continuous phase of concentrated emulsion, after the polymerization and removal of the dispersed phase, the porous polymer could be obtained. When OP^-10 is acted as emulsifier and xylene is as the dispersed phase, the stability of concentrated emulsion is achieved, and then the porous melamine resin was prepared by the concentrated emulsion polymerization. The ratio of monomers, the dispersed phase volume fraction, the emulsifier content and pH value of the concentrated emulsion system is analyzed. The materials were characterized by SEM, BET, EDS and FTIR, and the CO₂ adsorption performance of porous melamine resin is studied. The results indicated that when the monomer ratio of n?melamine?:n?formaldehyde? was 1:3, the volume fraction of dispersed phase was 85% and the content of emulsifier was 20 wt%, the CO₂ adsorption performance of porous material is the best, the CO₂ adsorption capacity reaches 1.52 mmol·g^-1, and it can be easily regenerated. In order to improve the CO₂ adsorption performance of the porous materials further, carbon nanotubes are added into porous materials. The results showed that the modified porous material has more CO₂ adsorption capacity, and enhances the thermal stability of the porous materials.