| Poly (aryl ether sulfone)s as a class of high performance engineering plastics are widely used since the early sixties of last century. Due to good film-forming and easy processing and different membrane prepared methods used, PAES is the most important industrial gas separation membrane materials. Developed by the U.S. Monsanto Prism film, silicone rubber is coated with PES to prepare asymmetric hollow fibers. By changing the structure of polymer chains and the introduction of nano-inorganic material to the polymer, scientific research workers are continually developping high performance gas separation membrane material in recent years. Biphenyl poly (ether sulfone) (PPSU) has better thermal stability, mechanical properties, excellent creep resistance, so that it has a better general properties than PES (PES). Because carbon nanotubes (CNT) had large aspect ratio and unique structure, they quickly became research focus of the chemistry, physics and materials science. Due to their smooth inner wall of the pore structure, the gas permeation rate in CNT is much faster than in other nano-porous materials having comparable pore sizes, thus they have a potential application in gas separation field.CNTs were modified using mixed acid oxidation. The surface carboxyl content of modified SWNT (f-SWNT) measured by acid-base titration increased significantly, the surface carboxyl content was 3.4% after 4 hours treatment. Morphologies of SWNT before and after treatment were observed by TEM. The results showed that the mixed acid oxidation method could remove the amorphous carbon and other impurities in SWNT, but aspect ratio remained relatively high. Since a large number of surface polar groups in f-SWNT existed, therefore f-SWNT can be well dispersed in the polar solvent NMP. Isotherm adsorption measurement results showed that the f-SWNT's surface area, pore volume and pore size decreased, indicating that some channels of CNT had been blocked CNT. In the future, modification conditions of CNT should be further optimized.PPSU molecular chains were designed.3.3'-disulfonic-4,4'-dichloro-diphenyl sulfone (SDCDS) and 3,3'-diallyl-4,4'-dihydroxy biphenyl (DABP) were successfully synthesized respectively and characterized by MS, DSC, FTIR and 'H-NMR separately. The results were consistent with the expected structures". Two series copolymer were synthesized by nucleophilic substitution reaction with adjustable ratio of the two monomers, i.e. sulfonated diphenyl poly (ether sulfone) copolymer (S-PPSU) and sulfonated quaternary copolymer containing allyl group (AS-PPSU), whose structures were proved by FTIR and'H-NMR. The sulfonation degree of S-PPSU ranged from 7.8% to 35.5%. S-PPSU and AS-PPSU in polar solvents have very good solubility. Thermal properties of polymers were characterized by DSC and TGA. As the presence of sulfonic group, the glass transition temperature (Tg) of copolymer compared with pure PPSU's increased significantly, Tg of S-PPSU with 10% content SDCDS is 256℃. But the thermal decomposition temperature decreased with the content of the sulfonic in copolymer increased.A series of mixed matrix membrane (MMM) with different CNT content were prepared by solution blending. Macroscopic phase separation was observed evidently in 1% SWNT/PPSU, but 1wt% f-SWNT dispersed uniformly in the S-PPSU matrix, no macroscopic phase separation observed. Morphology of MMM was observed by SEM. The results showed that the treated SWNT didn't aggregate in the matrix, which was due to the hydrogen bonding interactions between carboxy group of f-SWNT and sulfonic groups of the copolymer. From the FTIR results it showed that red shift of sulfonic group appeared and the absorption intensity decreased due to hydrogen bonding interactions.From DMA results it showed that the values of the tangent of loss angle of 1%f-SWNT/SPPSU dropped 11.3℃compared to the SPPSU's probabaly due to the stonger interactions between sulfonic groups of SPPSUsubstituted by strong interactions between sulfonic groups of SPPSUand a few carboxy group of f-SWNT. When the f-SWNT content increased to 5%. the interaction between carboxylic acid and sulfonic acid groups increased, mobility of polymer chains adsorbed in the surface of f-SWNT decreased. thus the value of tangent of loss angle increased to 237.4℃, the peak is also slightly wider. Mechanical properties test results showed that SPPSU had the similar tensile strength and tensile modulus compared to PPSU. With the f-SWNT content increased, tensile strength and Young's modulus increased to MMM film with PPSU and SPPSU matrix, but the MMM with S-PPSU matrix has better mechanical properties, probably due to f-SWNT in the S-PPSU matrix has better dispersion. So when external load acting on the MMM film, CNT can effectively transfer interface stress, thus improved the mechanical properties of MMM of SPPSU matrix.The gas separation membrane performance was studied. The results showed that with the introduction of sulfonic group permeability coefficient of PPSU reduced, at the same time the separation coefficient was enhanced. Compared with the PPSU based MMM, the introduction of CNT can obviously improve the permeability of MMM of SPPSU matrix. Permeability coefficient and the separation coefficient can be enhanced at the same time with the f-SWNT content increased.
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