Synthesis Of Pillar[5]arene-based Porous Organic Polymers And Their Adsorption Properties

Focusing on the theme of introducing pillararene into porous organic polymers,this paper designed and synthesized two kinds of porous organic polymers with different synthesis strategies,and explored the relationship between the structure and adsorption properties of them.(1)A pillar[5]arene-based porous organic polymer,namely,P[5]-TEB,was synthesized by Sonogashira cross-coupling reaction,then a novel polyhydroxyl polymer P[5]OH-TEB was obtained by demethylation reaction from the former polymer.The introduction of hydroxyl group makes the specific surface area of P[5]OH-TEB larger and the mesoporous distribution range wider,as well as introduced the microporous structure.By simulating the adsorption isotherm and adsorption kinetics curves of the two polymers on methylene blue,it was found that the maximum simulated adsorption capacity of P[5]OH-TEB on methylene blue was 4.5 times that of P[5]-TEB after the introduction of hydroxyl group,and the adsorption capacity was significantly increased with a faster adsorption rate;Selective adsorption experiments showed that the adsorption performance of the polymer to cationic dyes was improved after the introduction of hydroxyl group,which was related to the introduction of hydroxyl group.The introduction of hydrophilic hydroxyl group promotes its contact with cationic dyes in aqueous solutions.Meanwhile,electrostatic and hydrogen bond interactions exist between the hydroxyl group and cationic dyes.The synergistic interaction improves the adsorption effect of the polymer P[5]OH-TEB with hydroxyl group on cationic dyes,which is not conducive to its adsorption of anion dyes.This study provides a new research idea for the modification of pillararene-based porous polymers.Hydroxylation of pillararene improved the adsorption performance and selectivity of cationic dyes,which is expected to promote the application of porous polymers in the field of cation dye adsorption.(2)A nitrogen-rich porous polymer FPP5-BDG containing pillararene FPP5 and triazine structure was prepared by Schiff base reaction,its physical and chemical properties were studied.The polymer has excellent thermal and chemical stability.Nitrogen adsorption experiments showed that the polymer has abundant pore structure,and exists both micropore and mesoporous structure.The pore size is distributed in 1.5nm and 12.1 nm,and the specific surface area is 439 m~2/g.Iodine adsorption experiments show that compared with a similar structure of polymer PAN-FPP5,FPP5-BDG captured more iodine vapor,iodine adsorption quantity can reach 296 wt%,exceeding the adsorption values of most compounds reported so far.It also had good adsorption on iodine in solution,and the maximum simulated adsorption capacity obtained by adsorption isotherm simulation is 618.7mg/g.