Modified polysulfones. IV. Synthesis and characterization of polymers with silicon substituents for a comparative study of gas‐transport properties

Abstract

Wepreviouslyconductedadetailedstudyofgas-transportandotherpropertiesofaseriesofsiliconderivativesofUdelpolysulfone(PSf)andRadelpolyphenylsulfone;wenowreportthedetailsoftheirpreparationbythereactionoflithiated polymerintermediateswithchlorosilylalkylarylelectrophiles.Ortho-sulfone-substitutedpolymerswithpendanttrimethylsilyl,dimethylphenylsilyl,anddiphenylmethylsilylandothergroupswereobtainedbydirectmetalationfollowedbythereactionofthe dilithiatedintermediatewiththeappropriatesilylelectrophile.Inaddition,thestructuralregularityandgeometryofthedilithiatedsitewasalsoexploitedtointroduce siliconintothemainchainbythereactionofdichlorosilylelectrophiles,leadingtothe formationofanewtricyclicheteroatomring.Ortho-etherPSfderivativeswereobtained fromadibrominatedpolymerviathelithiationofbrominatedpolymerandreaction withasilylelectrophile.Thedegreeofsubstitutionofthesilylgroupswas2.0orless fromdilithiatedpolymersandwasdependentontheelectrophilereactivityandreaction conditions.AdetailedstructuralcharacterizationofthepolymersbyNMRandIRspectroscopyisreportedinadditiontoglass-transitiontemperaturesandthermalstabilities.

Removal of monodisperse liquid aerosols by using the polysulfone membrane filters

“…This work used three different concentrations of casting solutions (15,20 and 25%) to product the three kinds of PSF membrane filters and explored the effects of the different concentration-casting solutions on the aerosol penetration. Fig.…”

“…The obtained membranes were peeled off and air-dried completely at the ambient temperature. This work used casting solutions at three concentrations (15,20 and 25%) to yield the PSF membrane filters. The pores of the membrane filters typically decrease with the polymer concentration [24].…”

“…The chemical and physical attributes of PSF, including good thermal and chemical stability, mechanical strength and excellent oxidative resistance, make it a preferred material for use as a membrane substrate. Traditionally, PSF membrane filters have been widely utilized in water ultrafiltration systems [16,17], gas separation [18], ion-exchange membranes in electro-membrane processes, including electrodialysis and polymer electrolyte membrane electrolysis [19,20]. However, PSF membrane filters have seldom been employed in filtering and sampling aerosols.…”

Gas Transport Properties of Tetramethyl Polysulfones Containing Trimethylsilyl Group Side Substituents

“…Using this chemistry, we previously synthesized PSfs and PPSfs with sequentially increasing sizes of silicon substituents containing methyl and phenyl groups (13) and correlated their structural effect on gas transport properties (16). TMS substituents gave the most favorable properties with permeability coefficients for 0 2 increasing with DS and with minimal loss in 0 2 /N 2 permselectivity.…”

Filtration characteristics of polysulfone membrane filters

“…PSF is extensively employed as an thermoplastic material in fabricating membranes for use in water ultrafiltration systems (Kaeselev, Pieracci, & Belfort, 2001;Kilduff, Mattaraj, Pieracci, & Belfort, 2000) and gas separation, such as in stripping carbon dioxide from natural gas streams and producing highly pure nitrogen from air (Liu, Chakma, & Feng, 2004). In particular, PSF is also used in ion exchange membranes in electro-membrane processes such as electrodialysis and polymer electrolyte membrane electrolysis (Yoshikawa, Hara, Tanigaki, Guiver, & Matsuura, 1992;Guiver et al, 2001). However, PSF membrane filter has very been used less in aerosol filtration, such as in aerosol sampling (Cullen, Field, & Sherrell, 2001).…”