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The preparation of (A-B), block copolymers comprising of poly(ary1 ether-sulfone) (PSF) and poly(tetrahydr0furan) (PTHF) segments have been described. Pyridine-terminated PSF oligomers of controlled molecular weights were synthesized via nucleophilic aromatic substitution reactions. PTHF oligomers prepared by living cationic ring-opening polymerization processes using trifluoromethanesulfonic anhydride as the initiator, were terminated with the PSF oligomers. The resulting block copolymers with quaternary nitrogen linkages along the backbone were characterized by a variety of techniques including spectroscopy, and thermal and chromatographic analysis.Poly(ary1 ether-sulfone) (PSF, 1) and related materials have received substantial academic and industrial interest.' In spite of a series of important characteristics, PSF is hydrophobic, which precludes its use as a membrane material in aqueous systems. Previous attempts at imparting hydrophilicity to the PSF backbone include sulfonation followed by neutralization2 and preparation of block copolymers with water-soluble poly(ethy1ene oxide) ( PEO).3 These block copolymers were synthesized by the coupling reactions of PSF with terminal phenolic groups and PEO with hydroxy end groups with phosgene. Detailed characterization studies were not reported.PTHF contributes various desirable properties to the block copolymer system including hydrophilicity, hydrolytic stability, high abrasion resistance and excellent elastomeric properties such as low hysteresis, high flexibility and impact resistance at low temperature. Block copolymers of a polystyrene hard segment and poly( tetrahydrofuran) (PTHF) as the soft segment with AB, ABA and (A-B), architecture have been ~r e p a r e d .~We have extended the scope of PTHF-containing block copolymers to the preparation of PSF-PTHF (2). The aryl ether sulfone blocks of controlled molecular weights were prepared by the reactions of 4,4'-isopropylidenediphenol (bisphenol-A), 4,4'-dichlorodiphenyl sulfone (DCD PS) and 4-hydroxypyridine. Difunctionally active PTHF segments of desired lengths were prepared by living-ring opening cationic polymerization of tetrahydrofuran (THF) with t rifluoromethanesulfonic anhydride (TFMA). The structures of these block copolymers resemble those of PTHF-based ionenes (3,4).5,6 In this article, the synthesis and analysis of model compounds, the PSF and PTHF oligomers and the block copolymers will be described. Characterization techniques include, thermal, spectroscopic, chromatographic and intrinsic viscosity measurements. ExperimentalMaterials THF (Aldrich) was refluxed over sodium for 12 h. Benzophenone was added and the deep-purple solution was c r 2 4 Y = Spacer Group X = CI, Br

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High-molecular-weight polyketanils with flexible ether linkages were prepared by the reactions of N,N'-bis[a-(4-fluorophenyl)benzylidene))-1,4-benzenediamine with phenoxides derived from several less acidic diphenois. Molecular sieves mediated reactions of 1,4-benzenediamine with two equivalents of 4-fluorobenzophenone afforded the desired monomer in good yield. Formation of successive ether linkages via nucleophilic aromatic substitution reactions constituted the polymerforming step. The high-molecular-weight polymers form tough films upon compression molding, exhibit relatively high glass transition temperatures and good thermal stability. 0 1993, Hiithig & Wepf Verlag, Base1 CCC 0025-1 16)

A series of amorphous and semicrystalline poly(ary1 ether-bisketone)s have been synthesized from bisphenols and 4,4'-bis(p-fluorobenzoyl)biphenyl via nucleophilic aromatic substitution reactions. Model compound studies were carried out with a variety of substituted phenols, 4,4'-bis( p-fluorobenzoyl)biphenyl and 4,4'-bis( p-chloroben-zoy1)biphenyl. The bishalide monomers were synthesized by the reaction of biphenyl-4,4'-dicarboxylic acid with thionyl chloride followed by Friedel-Crafts acylation with the appropriate aryl halide. Potassium carbonate mediated reaction of these monomers in dimethylacetamide or diphenyl sulphone gave high-molecular-weight polymers in excellent yield. Polymers with semicrystalline morphologies were synthesized from soluble highmolecular-weight amorphous precursors with removable bulky substituents. Unlike the corresponding monoketone analogues, the amorphous poly(ary1 ether-bisketone)s exhibited poor solubility in a wide variety of solvents, indicative of improved solvent resistance. The glass-transition and melting temperatures of the polymers are among the highest known for poly(ary1 ether-ketone)s. In addition, the polymers exhibit excellent thermal stability and afford tough films by compression moulding.

The effects of N-methyl-2-pyrrolidinone (NMP) as solvent on the polymerizaton reactions of 1,3-bis(4-chlorobenzoyl)benzene (1,3-CBB) and 1,3-bis(4-fluorobenzoyl)benzene (1,3-FBB) with 4,4'-isopropylidenediphenol (bisphenol-A) were examined. The failure of these reactions to produce high molecular weight polymers in the presence of anhydrous potassium carbonate is due to dehalogenation of 1,3-CBB via substitution radical-nucleophilic unimolecular (SRNl) processes. On the other hand, 1,3-FBB undergoes nucleophilic aromatic substitution reactions (SNAR) with the carbonate anion at elevated temperatures. However, it is possible to synthesize high molecular weight polymers from 1,3-FBB and bisphenol-A in NMP either by first forming the bisphenoxide with stoichiometric amounts of aqueous sodium hydroxide or in the presence of anhydrous potassium carbonate at a lower reaction temperature.

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