Synthesis, Characterization And Application Of Porous Functional Ionic Polyurea Materials

Porous materials are widely used in the fields of gas separation,conversion and recovery due to their advantages such as large specific surface area,high porosity and excellent spatial structure.As a typical porous material,polyurea material contains urea groups,and its rigidity,melting point and polarity are relatively high.Therefore,it has excellent waterproof,wear-resistant and heat-resistant properties.The use of CO₂ directly or indirectly to prepare polyurea materials reduces the use of traditional highly toxic raw materials phosgene and uses the greenhouse gas CO₂,which not only achieves the purpose of green synthesis,but also has a positive effect on the ecological environment and social development.Currently,immobilizing ionic liquids in porous materials is one of the main ways to realize the functionalization of porous materials ions.Eutectic solvents are also called ionic liquids,and are widely used in the field of organic synthesis because of their low cost and easy synthesis.By adjusting the type of eutectic solvent,the growth of functional materials can be effectively regulated,so that functional materials can be prepared in a targeted manner.In addition,the use of eutectic solvents in the experimental synthesis can also avoid the danger of high pressure and promote the development of functional ionic materials.In this thesis,a porous functional ion polyurea material was prepared by solvothermal method using eutectic solvent and tris（4-aminophenyl）amine,and its ability to catalytically convert CO₂ was explored.The main research contents and conclusions are as follows:（1）Determine the molar ratio of the reactants according to the step cooling curve of ZnCl₂-urea,prepare a series of eutectic solvents for the reaction of urea and zinc chloride at different ratios,and use the solvothermal method to synthesize porous functional ion polyurea materials;（2）The above polyurea materials were characterized by infrared,thermogravimetric and other analytical methods,and the results showed that porous functional ion polyurea materials were successfully synthesized.According to the analysis of thermogravimetric and nitrogen adsorption results,select n（urea）:n（zinc chloride）products of 16:1 and 20:1,and find that the best reaction time of the material is 7 days;（3）The post-modification method and the one-pot method were used to quaternize the obtained porous functional ion polyurea material,and the obtained product was characterized by infrared and nitrogen adsorption;（4）The modified porous functional ion polyurea material was used to catalyze propylene oxide to produce propylene carbonate.The performance of the porous functional ion polyurea material to catalyze the conversion of CO₂ was evaluated.The yield is in the range of 2.66～27.21%.The study found that the porous functional ion polyurea material has a certain catalytic ability.