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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Macromolecules 24 (1991), S. 3838-3844 
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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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. 1977-1985 
    ISSN: 0887-624X
    Keywords: aromatic polyetherketone ; dibenzoburan ; etherification reaction ; potassium carbonate ; silica ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4-Fluorobenzophenone reacted with potassium carbonate in the presence of silica catalyst in diphenyl sulfone solvent to yield 4,4′-dibenzoyldiphenyl ether. This new etherification reaction was extended to three difluoro aromatic ketones. 4,4′-Bis(4-fluorobenzoyl)diphenyl ether (I) reacted with potassium carbonate to yield a crystalline poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene) (PEK) and 4,4′-bis{4-[4-(4-fluorobenzoyl)phenoxy]benzoyl}benzene (II) gave a crystalline poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-carbonyl-1,4-phenylene)(PEKEKEKK). 2,8-Bis(4-fluorobenzoyl)dibenzofuran (III) or 2,8-bis(4-chlorobenzoyl)dibenzofuran (IV) reacted with potassium carbonate to yield a poly(oxy-1,4-phenylene-carbonyl-2,8-dibenzofuran-carbonyl-1,4-phenylene) (PEKBK). The PEKBK was a noval amorphous polymer with the glass transition temperature of 222°C and it showed excellent thermal stability [T. Tanabe and I. Fukawa, Jpn. Pat., Kokai 64-74223 (1989)]. Several amorphous dibenzofuran type polyetherketone copolymers were prepared by coplycondensation of III with 4,4′-difluorobenzophenone (V) or 1,4-bis(4-fluorobenzoyl)benzene (VI) [T. Tanabe and I. Fukawa, Jpn. Pat., Kokai 1153722 (1989)]. © 1992 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 535-546 
    ISSN: 0887-624X
    Keywords: aromatic polyetherketone ; etherification reaction ; potassium carbonate ; trans-etherification ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular weight aromatic polyetherketone (PEK) was found to react with 4,4′-difluorobenzophenone (DFB) in the presence of potassium carbonate in benzophenone or diphenyl sulfone at 300°C, yielding low molecular weight PEK with fluorophenyl end groups, while neither polyetheretherketone (PEEK) nor poly-thioetheretherketoneketone was found to react under similar conditions. Reaction model experiments showed that 4-fluoroben-zophenone reacts with potassium carbonate at 300°C to yield benzoyldiphenyl ether and that benzoyldiphenyl ether undergoes spontaneous trans-etherification in the presence of potassium carbonate at 300°C. These results indicate that the overall reaction yielding PEK of reduced molecular weight consists essentially of DFB oligomerization followed by trans-etherification between the DFB oligomer and PEK. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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