Halomethylated polysulfone: Reactive intermediates to neutral and ionic film‐forming polymers

Abstract

SynopsisHalomethylation of polysulfone ( P S ) with C8H170CH2X ( X = Cl, Br) in the presence of SnX4 ( X = C1, Br) led to PS-CH2X ( X = C1 or Br or both) (Scheme 1 ) . Under controlled conditions, PS-CH,X could be isolated and retains the good film forming properties of PS itself. Interhalogen exchange reactions occur in the presence of SnX, ( X = C1, Br) under anhydrous conditions (Scheme l ) , or a quaternary ammonium phase transfer catalyst R*R3N+X -, under aqueous conditions (Scheme 2 ) . The exchange reactions with R*R,N+X -, are favored when R = C8-Clo, and with R = C, only if n-octanol is added; otherwise gelation occurs. Exchange in CHC13 is attributed to dehydrohalogenation (and generation of dichlorocarbene) of the solvent in the presence of tetrabutyl ammonium hydroxide. Further chemical modifications of PS-CH2X by reaction with strong nucleophiles, led to hydroxymethyl polysulfone, acetoxymethyl polysulfone, and t-butyl-oxymethyl polysulfone (Scheme 3). Hydroxymethyl polysulfone sometimes gels under basic hydrolytic conditions and is best obtained by methanolysis of PS-CH,-OAc. Both PS-CH,-OAc and PS-CH20t-Bu are very stable, and provide a way to generate PS-CH2Br on need by cleavage with HBr in acetic acid.Direct oxidations with DMSO or tetrabutyl ammonium dichromate (Scheme 4 ) or indirect oxidations (Scheme 5 ) produce polysulfone with pendent CHO, COzR and P03R groups. Finally, polysulfones with linker arms including, carboxy alkyl, hexaglycol or sulfonamido crowns are described (Scheme 6). The reaction products were characterized by 'H-and 13C-NMR. Double irradiation experiments, proved unequivocally, that the first substitution occurred on the B ring of the bisphenol A moiety (see Table I ) ; the second substitution occurs on the A ring in position a.Thermogravimetric analysis generally shows for all modified polysulfones an extra transition at a lower temperature. The area of this band agrees generally with the values expected from calculated substitution degrees. t Present address: Bar-Ilan University,

Pendant functional group copolyether sulfones: III. Modified copolyether sulfones with bisphenolic copper chelate

“…The reduced viscosity showed higher values with increasing DS, whereas T g and T 10 values, on the contrary, exhibited a decreasing tendency, as noted. 22 The chelate-modified polysulfones (PSFChs) were obtained by the reaction between CMPSFs of different DSs and the sodium salt of copper(II) bis(2,4-dihydroxybenzaldehyde) according to Scheme 1. Some of their characteristics are Materials, Nanoscience and Catalysis presented in Table 3.…”

Phenyltrimethylammonium Functionalized Polysulfone Anion Exchange Membranes

“…The introduction of functionality into PSf has been accomplished by copolymerization with functionalized comonomers or by postfunctionalization of commercially available polymers. Examples of the functionalization chemistry include sulfonation, 3 bromination, 4 chloromethylation, 5 amidoalkylation, 6 and lithiation. 7−9 Functionalized PSfs have been actively investigated as membrane materials for gas 1,2,10,11 and liquid separation 12 and for fuel cells (FCs).…”

Preparation and characterization of brominated polyethersulfones

“…Our experiences were negative in relation to the bromomethylation of PES; Warshawsky's bromomethylating agent, bromomethyl octyl ether, 6,9 failed when applied to this polymer. There was no reaction, even at reflux conditions.…”