Study On Gases And Iodine Adsorption Of Microporous Organic Polymers

Microporous organic polymers have been greatly developed in recent years and have been widely used in many fields such as gas adsorption and separation,semiconductor and catalysis.In this thesis,nitrogen-rich and hierarchical porous polymers contained triazine rings,benzene rings and N-H were synthesized by means of hyper-cross-linking.The chemical structures of polymers were characterized by NMR and FT-IR,and the porosity of the polymers was characterized by a physical adsorption instrument.Meanwhile the carbon dioxide and iodine adsorption properties of polymers were studied.（1）Hierarchical porous PAN-POTDAs were synthesized by the reaction of aldehydes with the quaternary amine（synthesized by isophthalonitrile）containing triazine rings structure.The specific surface area calculated by BET model was up to 1165m²g^-1.The ratios of micropore volume to total pore volume was up to 0.664,which also contributed to their good CO₂ adsorption capacity.The CO₂ adsorption capacity of PAN-POTDAs at 273K and 1bar was up to 13.16wt%,and PAN-POTDAs had a strong interaction with CO₂,whose maximum adsorption heat was up to 27.8 kJ mol^-1.Triazines and N-H favor interactions between iodine and polymers,and as a result,PAN-POTDAs had good iodine adsorption capacity up to 301.90wt%and also had very high adsorption efficiency of 174.23wt%within 20min.（2）Hierarchical porous PAN-MOTDAs were synthesized by the reaction of aldehydes with the quaternary amine（synthesized by terephthalonitrile）containing triazine rings structure.There were loss of specific surface area and micropores due to the increase of steric resistance of the monomer structure.The specific surface area calculated by BET model was up to 991m²g^-1.The largest of the ratios of micropore volume to total pore volume were reduced to 0.528,which also contributed to their smaller CO₂ adsorption capacity.The largest CO₂ adsorption capacity at 273K and 1bar was 10.21 wt%.However,the adsorption capacity of iodine vapor increased with the increase of mesoporous and macroporous content,which was up to 329.41wt%.Also,PAN-MOTDAs had relative high adsorption efficiency of 174.23 wt%within 20min.（3）Hierarchical porous PAN-TDATPAs were synthesized with hexamine which was introduced with the structure of triphenylamine.Because the tri-arm structure of triphenylamine is beneficial to the construction of pore channels,the specific surface area calculated by BET model was up to 1273 m²g^-1.The largest ratios of micropore volume to total pore volume was up to 0.655.Although the maximum CO₂ adsorption heat was a little decreased,benefited by the high content of micropores,the CO₂ adsorption capacity at 273K and 1bar was up to12.57wt%.With the increase of monomer functionality,the amount of N-H which can strongly interact with iodine molecules increased,and which resulted in good iodine adsorption capacity of 317.39 wt%.Besides,the adsorption rate of iodine vastly increased to 242.65 wt%within20min.（4）Hierarchical porous PAN-TPAHPZs were synthesized with hexamine which was introduced with the twisted andasymmetric structure of phthalazinone.Due to the large size of monomers,polymer chain segments were interpenetrated with each other,which led to the loss of pores and decrease of specific surface area.The largest specific surface area calculated by BET model was only 766 m²g^-1.The largest ratios of micropore volume to total pore volume was only 0.348.The CO₂ adsorption capacity at 273K and 1bar was only up to 6.39 wt%.Meanwhile,the maximum CO₂ adsorption heat decreased to 17.6 kJ mol^-1 under the influence of chain segments interpenetration.The decrease of microporous content and adsorption heat was the reason for the decrease of CO₂ adsorption.The loss of pore structure reduced the adsorption of iodine.The adsorption capacity was only up to 273.79 wt%and the adsorption efficiency was up to 146.32 wt%within 20min.