Design,Synthesis And Properties Of Organic Porous Covalent Frameworks Based On Pyrrolopyrrole

Organic nanoporous polymers have high specific surface area and porosity,low skeletal density,controlled chemical and physical properties,permanent open pore structure and diverse synthetic strategies.They can be widely used in gas loading,heterogeneous catalysis,Gas separation and heavy metal ion adsorption are hot topics in the research of porous materials.Two types of organic porous polymers based on pyrrolopyrrole were designed and synthesized.The first one is synthesized from p-bromobenzene cyanide and p-bromobenzaldehyde as the raw material of pyrrolopyrroles tetrabromide product CNPP-1.After determining the structure by infrared spectroscopy and nuclear magnetic resonance spectroscopy,it is utilized under anhydrous anaerobic conditions.A novel pyrrolopyrrole tetrabromo-based conjugated microporous polymer CMP-Br was prepared by Yamamoto coupling reaction.The structure,surface morphology and pore size distribution of the polymer CMP-Br were analyzed by means of FT-IR,TGA,SEM,TEM and BET.The polymer CMP-Br has excellent chemical stability and thermal stability.It is an amorphous polymer material with a microscopic morphology of agglomerated particles.The low pressure critical nitrogen adsorption and desorption experiment shows that the specific surface area of the material is 300 m²/g.It has the same specific surface area under many other identical conditions.The second one is to obtain three monomers:CH₃-N,CN-N and 4CNPP through the domino ring-forming reaction,and then catalyzed polymerization of high-temperature molten zinc chloride under anhydrous anoxic argon to obtain CTF-CH₃-N,CTF-CN-N and CTF-CN,Three polymers were characterized by FT-IR,TGA,SEM,TEM and BET for structural characterization,surface morphology and pore size distribution.The pores of three porous materials were effectively regulated and their gas adsorption properties were studied.Firstly,the common industrial raw materials p-aminophenyl cyanide and p-cyanobenzaldehyde were selected as the starting units.Through a series of reactions,the heterocyclic 4CNPP was obtained.Based on the traditional zinc chloride ion thermal catalysis,the polymerization process was optimized and a new type of three was prepared.The azine-based nanoporous polymer(low-pressure critical nitrogen adsorption-desorption experimental characterization method proves the feasibility of the optimization process.The experimental results show that the specific surface area of the material is 1513m²/g.The carbon dioxide adsorption performance and selectivity of the material are studied.The methane and carbon dioxide loadings were 19.24 cm³/g and 61.21 cm³/g,respectively,and the adsorption heat of carbon dioxide was 22.6 KJ/mol.