Sulfone polymers description

Sulfonated polybenzoimidazole (sPBI) membranes have also been prepared by poly condensation of 2-sulphoterephthalic acid with 1,2,4,5-tetraaminobenzene tetrahydrochloride [193] or by grafting alkyl or aryl sulfonates on to the imidazole ring [194]. ABPBI was sulphonated by immersion in sulfuric acid followed by heat treatment at 450 °C [195]. Other methods of sulphonation have been reviewed by Asensio et al. [196], along with a detailed description of the properties of PBI blends with sulfonated and non-sulfonated polymers, and block PBI copolymers. 

The phenylated polyphenylene oxide (0 P 0 0) was sulfonated using a slightly modified procedure of Makowski et al. A detailed description of the sulfonation and some properties of these materials is reported elsewhere . Sulfonated polymers (S 0 P 0 0 Acid) with equivalent weights of 1200, 600 and 510 were used for blending with ethyl acrylate copolymers. 

The chemical structure of electrically conducting polypyrrole films doped with p-toluene sulfonate and dodecyl sulfate was studied by FT-Raman spectroscopy. The spectra were compared with those from the corresponding reduced polymers after dedoping and found to be consistent with polaron and bipolaron descriptions of the electron transport mechanism in polypyrrole (331). 

Sundhohn s research was well summarized in a review article [ 129], including the description and characterization of novel polymer electrolyte membranes for low-temperature fuel cells. Membranes made of PVDF-g-PSS A graft copolymers, cross-linked by divinylbenzene (and/or bis(vinylphenyl)ethane) [131,134,135], were compared with noncross-hnked membranes. The authors observed that the ion conductivity of the cross-hnked membranes was lower than that of noncross-hnked ones (induced by the inefficient sulfonation of the cross-linked materials and also by low water uptake at a low degree of grafting). Confocal Raman spectroscopy was used to characterize the PVDF-g-PSS A membranes in fuel cell conditions [136], finding that the cross-hnked membranes did not undergo the degradation noted with the noncross-hnked films. 

The sulfobutylation experiment was conducted in such a way that HNPAEK-xx was dissolved in dry NMP or DMSO and the hydroxyl groups were deprotonated with NaOH first and then reacted with excessive 1,4-butane sultone. General description 1 g HNPAEK-80 (2.59 mmol hydroxyl groups) was dissolved in 20 mL DMSO in a three-necked flask. 0.2 g NaOH (5 mmol) was then added to the solution and the reaction mixture was stirred for 6 h at room temperature. 0.39 g 1,4-butane sultone (2.85 mmol) was then added dropwise to the solution, and the reaction was heated to 160°C, stirred at that temperature for 12 h. The resulting sulfonated copolymers were precipitated in 250 mL acetone and washed by boiling water several times. The obtained polymer was immersed in a large excess of HCl (5 wt.%) solution over 24 h to make the salt form convert into the acid form. The product (SNPAEK-80) was finally dried in a vacnnm at 80°C. 

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