Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Thermotropic copolyesters. III. Synthesis and characterization of liquid crystal copolyesters containing the bicyclo[2.2.2]octane ring system (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2405-2422 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A number of thermotropic copolyesters which contain the bicylo[2.2.2]octane ring system have been synthesized. Because of the stiffening effect of the bicyclo[2.2.2]octane group on the chain, the sebacoyl spacer was used to obtain meltable compositions.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080260913
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Aromatic polyamides containing keto-benzocyclobutene pendants (1996)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 3539-3549 
    Details
    ISSN: 0887-624X
    Keywords: benzocyclobutene ; polyamides ; crosslinking ; rigid-rod molecular composites ; poly(p-phenylenebenzobisthiazole) ; 3,5-diaminophenyl-4-benzocyclobutenyl ketone ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of novel benzocyclobutene (BCB)-pendanted polyamides (inherent viscosities: 0.20-0.69 dL/g) was synthesized from 3,5-diaminophenyl-4-benzocyclobutenyl ketone, and terephthaloyl, isophthaloyl, 4,4′-oxydibenzoyl chlorides, as well as 4,4′-(o-phenylenedioxy)dibenzoyl chloride. The DSC studies demonstrated that the BCB crosslinking exothermic transition occurred at nearly the same temperature (max. ∼ 275°C) for all the four polyamides, and they were thermally stable up to 380°C in helium, where the weight loss started to occur. TGA and DSC studies in air indicated that the polymers, in contrast to the model compound, showed evidence of oxidation just prior to or occurring simultaneously with the BCB crosslinking reaction. This could be attributed to the oxidation of the reactive diene generated from the ring-opening of the BCB competing with the process of two BCB pendant units approaching each other for crosslinking reaction. Preliminary examination of the BCB-pendanted polyamide regenerated from a methanesulfonic acid solution indicates that the BCB ring is quite stable (DSC evidence) in the strong acid medium. © 1996 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and thermal properties of thermosetting bis-benzocyclobutene-terminated arylene ether monomers (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2637-2651 
    Details
    ISSN: 0887-624X
    Keywords: benzocyclobutene ; cesium fluoride ; 4-hydroxybenzocyclobutene ; 4-trimethylsiloxybenzocyclobutene ; thermosets ; arylene ether monomers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of new bis-benzocyclobutene-endcapped arylene ether monomers was prepared and characterized. Whereas 2,6-bis(4-benzocyclobutenyloxy)benzonitrile (BCB-EBN) could be prepared in good yield using the standard procedure (K2CO3/NMP/toluene/Dean-Stark trap/120°C), other bis(benzocyclobutene) (BCB)-terminated monomers containing ether-benzophenone (BCB-EK), ether-phenylsulfone (BCB-ES), and ether-6F-benzoxazole (BCB-EBO) moieties were invariably contaminated by mono-endcapped products under similar reaction conditions. This can be attributed to a much greater activating effect of the nitrile group on the ortho-fluorides in the aromatic nucleophilic displacement reaction than the carbonyl, sulfonyl, and benzoxazolyl groups. However, the latter monomers could be synthesized (70-80%) from 4-trimethylsiloxybenzocyclobutene and respective aromatic fluorides in the presence of CsF at 140°C. Similar curing behaviors under N2 (DSC: extrapolated onset and peak temperatures at 227-230° and 260-262°C, respectively) characterized all four monomers. BCB-EK, BCB-ES, and BCB-EBN showed melting transitions at 108, 119, and 146°C, in that order. As BCB-EBO contained more rigid benzoxazole segments, it only exhibited a glass transition (Tg) at 85°C prior to curing exotherm, after it had been previously heated to 125°C. The following Tgs were observed for the cured materials: BCB-EK (201°C), BCB-EBN (224°C), BCB-ES (264°C), and BCB-EBO (282°C). The relative thermal stability according to TGA (He) results is: BCB-ES 〈 BCB-EBN 〈 BCB-EK 〈 BCB-EBO. Finally, the results from thermal analysis, infrared spectroscopic, and variable temperature microscopic studies indicated that the nitrile group plays an important role in the cure chemistry, thermal, and microstructural properties of BCB-EBN. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2637-2651, 1998
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 4
    Electronic Resource
    Electronic Resource
    Structural investigations on lewis acid mediated solubilization of poly(p-phenylenebenzobisthiazole) in an aprotic solvent (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 31 (1993), S. 1965-1973 
    Details
    ISSN: 0887-6266
    Keywords: poly(p-phenylenebenzobisthiazole) ; Lewis acid ; Lewis base ; complexation ; mediated solubilization ; aluminum chloride ; nitromethane ; aprotic solvent ; electron donor-acceptor complex ; processing ; spectroscopic evidence ; structural changes ; stability of the complex ; decomplexation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Investigations on aluminum chloride-mediated solubilization of poly(p-phenylenebenzo-bisthiazole), PBZT, in nitromethane revealed that, in general, dilute solutions of the polymer prepared in nitromethane with a large molar excess of the Lewis acid with respect to PBZT were relatively stable and thus suitable for processing into films and coatings via regeneration with hydroxylic nosolvents while polymer solutions with minimum stoichiometrically required (PBZT:AlCl3 molar ratio 1:4) or marginal molar excess of AlCl3 relative to PBZT tended to gel during handling. Structural studies on polymer-Lewis acid complex solutions were performed using 1H and 27Al NMR. 1H NMR of the protonated structure of the model compound 2,6-diphenylbenzo [1,2-d:4,5-d′] bisthiazole was useful for confirming the 1H NMR assignments of PBZT-AlCl3 complex solution in CD3NO2. 27Al NMR was particularly useful in probing the different tetrahedrally coordinated environments of the Al nucleus in the polymer solution, pointing to a complexation interaction between the polymer molecule and the Lewis acid and also between the solvent and the Lewis acid. Direct evidence in the solid state for the presence of a reversible electron donor-acceptor complex (EDA complex) was obtained from FTIR spectra of complexed films, isolated and handled in an inert atmosphere. The structural changes upon PBZT complexation caused significant frequencly shifts in both aromatic as well as heteroring stretching modes relative to PBZT itself, and intensity variations indicative of changes in the resonance configuration between the 1,4-phenylene moiety and the aromatic heterocyclic ring were also observed upon complexation. A preliminary comparison between the pristine PBZT fibers and regenerated PBZT by dilute solution viscometry indicates that the process results, to some extent, in polymer degradation leading to a decrease in the molecular weight of the polymer © 1993 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1993.090311308
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A Nitrate Salt of a Hydrazine-Formaldehyde Polymer (1986)
    Weinheim : Wiley-Blackwell
    Propellants, Explosives, Pyrotechnics 11 (1986), S. 188-188 
    Details
    ISSN: 0721-3115
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prep.19860110607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...