ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 2741-2752 
    ISSN: 0887-624X
    Keywords: 3,3′-bis (4-flurobenzoyl) biphenyl ; poly (aryl ether ketone)s ; spectroscopic prop-erties ; thermal properties ; thermomechancial properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A monomer, 3,3′-bis (4-fluorobenzoyl) biphenyl, was prepared in high yield in two steps from inexpensive 3-chlorobenzoyl chloride and fluorobenzene, and polymerized by nucleophilic displacement reaction with various bisphenol monomers in tetramethylene sulfone to produce a series of high molecular weight poly(aryl ether ketone)s containing 3,3′-dibenzoylbiphenyl (DBBP) moieties. The spectroscopic, thermal, and thermomechanical properties of these polymers and related isomeric polymers having 2,2′-and 4,4′-DBBP units were determined and compared to study the effects of changes in the substitution pattern of the biphenyl unit. Except for the 2,2′-DBBP series of polymers, Tgs were found to increase with increasing linearity of the DBBP unit. The 2,2′-DBBP series of polymers had exceptionally high Tgs due to the sterically restricted motions in the biphenyl unit caused by the 2,2′-substitution. In addition, they also showed evidence for torsion with the 2,2′-DBBP unit, whereas in other isomeric polymers the DBBP units are believed to be relatively coplanar. Thermal stabilities and tensile moduli for these polymers proved to be independent of substitution patterns. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 1627-1635 
    ISSN: 0887-624X
    Keywords: binaphthyl dianhydride ; polyimides ; synthesis ; property ; fluorescence ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4,4′-Binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride was synthesized from 4-chloro-1,8-naphthalic anhydride and polymerized with aromatic and pliphatic diamines in m-cresol or N-methyl-2-pyrrolidinone (NMP). The polyimides, except for two derived from p-phenylenediamine and hydrazine, are soluble in 1,1,2,2-tetrachloroethane and NMP. Their intrinsic viscosities ranged from 0.36 to 2.20 dL/g. The polymers showed excellent thermal and thermooxidative stabilities and displayed weak glass transition temperatures. Young's moduli of some polymer films were in the range of 2.5 and 5.4 GPa at 30°C. The aliphatic polyimides exhibited a stronger fluorescence than the aromatic polyimides. © 1995 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 9-16 
    ISSN: 0887-624X
    Keywords: soluble optically active azo copolymethacrylate ; photoisomerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of soluble optically active block copolymers of trityl methacrylate (TrMA) and cyclohexyldiphenylmethyl methacrylate (CHDPMA) with methyl methacrylate (MMA) and n-butyl methacrylate (n-BuMA) were synthesized using the complex of 9-fluorenyllithium and (S,S)-(+)-2,3-dimethoxy-1,4-bis(dimethylamino)butane as an initiator in toluene at -78°C. Soluble optically active random copolymers derived from TrMA and azo methacrylates, 6-(4-phenylazophenoxy)hexyl methacrylate (PAHM) and 2-(4-phenylazophenoxy)ethyl methacrylate (PAEM), were obtained under similar anionic polymerization conditions. Optical activities of the copolymers largely depended on the weight percentage of TrMA or CHDPMA component in the polymer chains. Solubility and film formability were significantly improved for the copolymers. Irradiation of optically active TrMA-MMA and CHDPMA-MMA block copolymer films containing photoacid, diphenyl-p-tolylsulfonium triflate, causes the partial hydrolysis of bulky esters and results in the conformational randomization of helical chains, which in turn leads to a significant change in optical rotation of the films. Photoisomerization studies of azo-containing random copolymers indicate that the trans to cis isomerization induces the helical conformation racemization in solution. © 1997 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1349-1353 
    ISSN: 0887-624X
    Keywords: alternating ; copolyimide ; tetrahydro[5]helicene ; [5]helicene ; solubility ; molecular modeling ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of novel copolyimides have been synthesized from three commercially available dianhydrides and two diamine monomers containing the tetrahydro[5]helicene unit. Some of the copolyimides were soluble in common organic solvents such as 1,1,2,2-tetrachloroethane, N,N-dimethylacetamide, and N-methyl-2-pyrrolidinone. Molecular modeling was used to explain the enhanced solubility of the presented polyimides, based on structural features of the tetrahydro[5]helicene monomeric units. The onset temperatures for 5% weight loss for these polyimides, as assessed by thermogravimetry, were above 430°C in nitrogen. Inherent viscosities of the obtained polyimides were above 0.36 dL/g. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1349-1353, 1998
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 35 (1989), S. 679-682 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 19 (1996), S. 478-480 
    ISSN: 0935-6304
    Keywords: Capillary zone electrophoresis ; Chiral separation ; Cyclodextrins ; Methoxamine ; Lobeline ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0935-6304
    Keywords: Capillary zone electrophoresis ; Chiral separation ; Cyclodextrin ; Anisodamine ; Glycopyrronium ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 20 (1997), S. 298-299 
    ISSN: 0935-6304
    Keywords: Capillary zone electrophoresis ; Enantiomer separation ; Cyclodextrins ; Amphetamine ; Phenylephrine ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1434-193X
    Keywords: Sharpless asymmetric dihydroxylation ; Asimilobin ; Tetrahydrofuran ring ; Wittig reactions ; Annonaceous acetogenins ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The most efficient method for the synthesis of the trans/threo/trans-bis(tetrahydrofuran) (THF) ring unit was established, and the first total synthesis of (-)-asimilobin and its diastereomer was then accomplished in twelve and fourteen steps, respectively, from trans-1,5,9-decatriene, by a convergent route with a Wittig reaction as the key step. By virtue of these synthetic results, the absolute configuration of the bis(THF) unit in naturally occurring asimilobin should be corrected.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 34 (1996), S. 731-736 
    ISSN: 0887-6266
    Keywords: poly(aryl prehnitimide)s ; bent diimide ; ac impedance ; dielectric constant ; permittivity ; loss tangent ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Six different variants of a new type of polyimide, poly(aryl prehnitimide)s, containing various moisture contents have been studied using dielectric relaxation spectroscopy. Dielectric loss measurements show the presence of a double peak near 200 K (depending on frequency) due to water relaxation. The two peaks have been designated γ1 and γ2. The γ2 peak appears as a shoulder on the γ1 peak at lower temperatures and is very sensitive to moisture content. The γ1 peak is less sensitive to moisture content and is associated with isolated water molecules coupled to the polymer chains. Both of the γ-relaxation peaks were studied in detail to obtain the associated activation energies. © 1996 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...