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  • 1
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of high-molecular-weight amorphous and semicrystalline poly(aryl ether bisketone)s were prepared from bisphenols and 3,4′-bis(4-fluorobenzoyl)biphenyl via nucleophilic aromatic substitution reactions. Model compound studies were carried out with several substituted monohydric phenols, 3,4′-bis(4-fluorobenzoyl)biphenyl and 3,4′-bis(4-Chlorobenzoyl)biphenyl. The dihalo-substituted aromatic ketones were synthesized by the reaction of 3,4′-biphenyldicarboxylic acid with thionyl chloride, followed by Friedel-Crafts acylation with the appropriate aryl halide. The required dicarboxylic acid was prepared starting from 4-bromotoluene and 3-methylcyclohexanone. Potassium carbonate mediated reaction of the monomers in dimethylacetamide or diphenyl sulfone gave high-molecular-weight polymers in excellent yield. The glass transition temperatures of the polymers are in the 170 to 190°C range. In addition, the polymers exhibit excellent thermal stability, as evidenced by both dynamic and isothermal thermogravimetric analysis, and afford tough films by compression molding.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 2085-2097 
    ISSN: 0887-624X
    Keywords: imide-aryl ether ketone block copolymers ; multiphase morphologies ; mechanical and thermal properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Imide-aryl ether ketone block copolymers were prepared and their morphology and thermal and mechanical properties investigated. Two aryl ether ketone blocks were incorporated; the first was an amorphous block derived from bisphenol-A and the second block was a semi-crystalline poly(aryl ether ether ketone) prepared from a soluble and amorphous ketimine precursor. Bis(amino) aryl ether ketone and aryl ether ketimine oligomers were prepared via a nucleophilic aromaic substitution reaction with molecular weights ranging from 6,000 to 12,000 g/mol. The oligomers were co-reacted with 4,4′-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) diethyl ester diacyl chloride in N-methyl-2-pyrrolidone (NMP) in the presence of N-methylmorpholine. The copolymer compositions, determined by H-NMR, of the resulting amic ester based copolymers ranged from 8 to 50 wt % aryl ether ketone or ketimine content. Prior to imide formation, the ketimine moiety of the aryl ether ketimine block was hydrolyzed (p-toluene sulfonic acid) to the ketone form producing the aryl ether ether ketone block. Compositions of this block were maintained low to retain solubility. Solutions of the copolymers were cast and cured to effect imidization, producing clear films with high moduli (ca. 2200 MPa) and elongations (33-100%). The copolymers displayed good thermal stability with decomposition temperatures in excess of 450°C. Multiphase morphologies were observed irrespective of the co-block type, block length or composition. © 1992 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of controlled molecular weight poly(aryl ether sulfone) oligomers with benzophenone moieties at the chain termini were prepared. The two carbonyl groups at the chain ends were converted to ethynyl groups by using trimethylsilyldiazomethane/BuLi in tetrahydrofuran. Reactions of 4,4′-isopropylidenediphenol with 4,4′-difluorobenzophenone and 4-fluorophenylphenylacetylene as the end-capping reagent in N,N-dimelthylacetamide afforded the desired poly(aryl ether ketone) oligomers Both sulfone and ketone containing oligomeric polyethers undergo crosslinking reactions at elevated temperatures.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effects of N-methyl-2-pyrrolidinone (NMP) as solvent on the polymerization 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 (SRN1) 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.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 40 (1990), S. 1177-1194 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In recent years, tetraethyl orthosilicate (TEOS) has been used as a precursor in preparing inorganic glasses. The technique, known as the sol-gel process involves a two step poly(hydrolysis-condensation)reaction sequence. The work presented here is concerned with the utilization of a suitably functionalized oligomeric “glassy” organic polymeric component in this two step sequence. In particular, an amine terminated amorphous poly(arylene ether) ketone, (PEK), end capped with isocyantonropyl triethoxy silane was used to synthesize a hybrid network with TEOS. Low incorporation of the PEK oligomers into the network caused by early vitrification can be eliminated by carrying out reactions at elevated temperatures. A systematic change in mechanical and physical properties of the hybrid glass has been found with TEOS content and the annealing temperatures. A model for the network has been proposed based on structural and morphological evidence.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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