Melamine Based Porous Polymeric Materials:Synthesis And Their Carbon Dioxide Adsorption Properties

With the human activities intensifying, more and more carbon dioxide emitsinto the atmosphere. The control of COa emission is an imperative task due to the intensified greenhouse effect. Developing technology of CO2 capture and separation as well as the new type of CO2 adsorbents are of significance for the relief of greenhouse effect. Porous amine-based organic polymeric materials have large quantity of amino groups and vigorous pore structures, which show a good prospect in the application of CO2 adsorption and separation. This thesis focuses on the construction of melamine based porous polymeric materials through the polycondensation by using melamine as building blocks followed by investigation of their CO2 adsorption properties. The main work consists of two parts as follows:1) Phloroglucinol-melamine-formaldehyde (PMF) fibrous materials were prepared thorough the hydrothermal polycondensation by using melamine.formaldehyde and phloroglucinolas starting materials. Various techniques such as SEM, TEM, N2 adsorption-desorption, FTIR, TG etc. were applied to characterize the morphology, pore structure, functional groups and thermo-stability of the as-synthesized PMF fibrous materials. The results showed that the PMF materials exhibit fibrous structure with diameters ranging from 10 to 200 nm and specific surface areas of 20 to 140 m2/g depending on the ratios of the starting materials. Additionally, the PMF materials display good thermo-stability. The CO2 adsorption properties were investigated by a volumetric method, showing a CO2 adsorption amount of 1.3 mmol/g@298 K,100 kPa. Breakthrough column results indicates that CO2 has longer retentive time and the CO2-N2 can be separated on the synthesized PMF materials. Carbonization was applied on the the PMF material in order to improve the CO2 adsorption properties. The PMF kept the fibrous structure when the carbonization temperatures were 700 or 800℃, while a higher temperature of 900℃ could destroy the PMF structure. FTIR shows that the number of functional groups was greatly reduced after carbonization. The N2 adsorption results indicate that the specific surface area and pore volume are greatly improved after carbonization. Additionally, the CO2 equilibrium adsorption amount is significantly enhanced for the carbonized sample, which is up to 2.6 mmol/g@273 K,100 kPa.2) Melamine-phthalaldehyde (MP) microporous polymeric materials were synthesized by usingmelamine andterephthalaldehydeas starting materials. The effects ofsolvent, proportionsofstarting materials and additives such as acetic acid or benzene on the structures and properties of the synthesized MP microporous polymeric materials have been investigated. Additionally, the reaction temperature and the addition of catalyst and alkali ions have also been optimized in the case of sulfolane as the solvent. The results indicate that DMSO is the optimal solvent. MP microporous polymeric materials with specific surface area and CO2 adsorption amount of 581 m2/gand 1.1 mmol/g@298 K,100 kPa, respectively, can be synthesized. The control of reaction rate is of importance for the construction of the MP pore structures.