Engineering polymers based on 1,1-diphenylethylene derivatives: polymer substrates as precursors for membrane development

Abstract

A series of new, well-defined poly(ether ether sulfone), poly(ether ether ketone) and polyimide derivatives containing the diphenylethylene moiety were prepared by step-growth polymerization methods. Poly(ether ether sulfone) derivatives were prepared by two step-growth polymerization methods: (a) The cesium fluoride catalyzed polycondensation reactions of 4,4´-difluorodiphenylsulfone with different mole percentage ratios of silylated bisphenol derivatives, 2,2-bis(4-tbutyldimethylsiloxyphenyl) propane and 1,1-bis(4-t-butyldimethylsiloxyphenyl)ethylene in N-methyl-2-pyrrolidone at 150 °C. (b) The potassium carbonate catalyzed nucleophilic aromatic substitution polycondensation reactions of 4,4´-difluorodiphenylsulfone with different mole percentage ratios of bisphenol A and 1,1-bis(4-hydroxyphenyl)ethylene in N,N-dimethylacetamide and toluene at 165 °C. Poly(ether ether ketone) derivatives were prepared by the cesium fluoride catalyzed polymerization reactions of 4,4´-difluorobenzophenone with different mole percentage ratios of 2,2-bis(4-t-butyldimethylsiloxyphenyl)propane and 1,1-bis[4-(t-butyldimethylsiloxy)- phenyl]ethylene in N-methyl-2-pyrrolidone at 150 °C. Polyimide derivatives were prepared by step-growth polymerization methods by the polycondensation reactions of 4,4´-oxydiphthalic anhydride with different mole percentage ratios of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 1,1-bis(4-aminophenyl)ethylene. The intermediate polyamic acids were subjected to thermal imidization processes to provide the corresponding polyimide derivatives. Due to the regiospecific introduction of the 1,1-diphenylethylene group along the polymer backbone, the different poly(ether ether sulfone), poly(ether ether ketone) and polyimide derivatives were subjected to post-polymerization sulfonation reactions via the thiol-ene reaction using sodium 3-mercapto-1-propane sulfonate as sulfonating agent and AIBN as initiator in N-methyl-2-pyrrolidone/dimethylsulfoxide at 75 °C for 5 days. The 1,1- diphenylethylene derivatives and the different polymeric compounds were characterized by size exclusion chromatography, dilute solution viscometry, 1H NMR and 13C NMR spectrometry, FTIR spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, atomic force microscopy, transmission electron microscopy, elemental analysis, energy dispersive spectroscopy and ion exchange capacity measurements.