Preparation And Properties Of Amino-poly(Arylether Ketone) Gas Separation Membranes

Membrane-based gas separation technology has been rapidly developed with the continuous development of industrialization in recent years.Compared with traditional separation technology,membrane separation technology is a new"green"technology.Because of its simple equipment,low cost,low energy,environmental friendliness and easy operation,it has become a research hotspot.There is a mutual constraint between the permeability and selectivity of gas separation membranes,so it is urgent to research a membrane material with high permeability and selectivity.A glassy aromatic polymer having a rigid benzene ring in the bone chain was often used for separating membrane materials because of its high selectivity,mechanical properties,chemical stability,and continuous operation at high temperatures.However,the aromatic polymer membrane has a low permeability and is inefficient in actual production.Wherefore,the polyaryl ether ketone membrane material with higher selectivity was selected in this paper,and the amino groups?-NH₂?was introduced to improve the separation performance of the polymer membranes.On the other hand,the addition of bulky rigid fluorene groups and trifluoromethyl groups?-CF₃?further increases the selectivity of the polymer membranes.In this paper,a bisphenol functional monomer with amino groups was prepared,and a series of amino-containing polyaryletherketone polymers?Am-PAEK?with different amino groups were prepared by solution polycondensation.FT-IR spectroscopy showed that the polymer was successfully prepared.The Am-PAEK membranes have great thermal stability confirmed by the TGA and DSC test,and the highest tensile strength and Young's modulus of the Am-PAEK membrane could reach 53.76 MPa and 2252 MPa,respectively.Am-PAEK-10%showed a higher gas permeability P?CO₂?=12.38 and a higher selectivity??CO₂/CH₄?=21.34.The results show that the Am-PAEK-10%has the best separation performance and has potential for application to gas separation membrane materials.In order to further increased the selectivity of the poly?aryl fluorene ether ketone?membranes,we introduced bisphenol fluorene monomer having bulky rigid fluorene groups,and bisphenol AF monomer containing-CF₃.A series of amino-containing polyarylene ether ketone polymers?Am-PAFEK-X?having different contents of fluorene were prepared by melt polycondensation.Am-PAFEK-X was successfully prepared by ¹HNMR and FT-IR.And Am-PAFEK-60%had the highest glass transition temperature?Tg?of 210°C.This was because the steric hindrance effect of the fluorene groups effectively increased the rigidity of the polymer.However the thermal stability and mechanical properties of the polymer Am-PAFEK-X also meet the requirements of gas separation membranes.The selectivity of Am-PAFEK-60%membrane was??CO₂/CH₄?=27.47,and??CO₂/N₂?=31.13.All of above,the prepared poly?aryl fluorene ether ketone?polymer with high selectivity was expected to be used in the gas separation membrane materials.