Aromatic polysulfones containing functional groups by synthesis and chemical modification

Aromatic polysulfones containing functional groups were prepared by two synthetic approaches: by copolymerization of a carboxyl containing bisphenol monomer, or by chemical modification of polysulfones. A bisphenol 50 with a pendant fluorene ring was prepared by acid catalyzed phenol condensation of 9-fluorenone-4-carboxylic acid 53. Ionomeric polymers 56 and 57 were obtained by copolymerization of the alkali metal salts of bisphenol 50 and 0-50% of Bisphenol-A with a 4-4'-dihalodiphenylsulfone. The polymers are hydrophilic and have high thermal stabilities and glass transition temperatures. Polymers containing a diversity of functional groups were obtained by direct metalation of Udel 1 or Radel 2 polysulfones. Using organo-lithium metalating agents, the site of lithiation (Figure 6) was exclusively ortho- to the directing sulfone group. A maximum of three lithium atoms per repeat unit could be placed on the polymer chain without degredation. The reaction of electrophiles with the reactive metalated polymer intermediates led to polymers with alkyl, carboxyl, hydroxyl, silyl, halogen and other functional groups. Halogenated polymers 86, 89, and 90 were also prepared by halogenation of polysulfones without a catalyst. The site of halogenation was ortho- to the ether linkages in the bisphenol unit and this underwent metal-halogen exhange preferentially over the site of direct metalation.Peer reviewed: NoNRC publication: Ye