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  • 1
    ISSN: 1076-5174
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Relative response factors (molar sensitivities relative to dibutyl phthalate) for homologous series of n-alkanes (C12—C26), trimethylsilyl esters of C10—C20 fatty acids (FAs) and bistrimethylsilyl derivatives of C8—C16 ω-hydroxy fatty acids (HOF As) were determined by integration of total ion chromatograms obtained using a conventional gas chromatograph-mass spectrometer in the electron impact ionization mode. For the alkanes up to C22 and for the FA-TMS derivatives up to C18 (C21 including the TMS carbons), response factors increased linearly with total number of carbons (r2 〉 0.99). The slope of this correlation (response factor = 0.0775n - 0.338, where n is the total number of carbon atoms in each analyte) is essentially identical with those determined in earlier studies for smaller molecules not containing silicon. For the HOFA derivatives up to C14 (C20 including TMS carbons), the molar response factors also increased linearly with total number of carbons, but for reasons not yet apparent the regression line for these homologs was different (response factor = 0.0330n + 0.456; r2 〉 0.99). Response factors for higher homologs in all three series fell below the regression line for the lower homologs, the deviation increasing with increasing molecular mass and increasing GC retention time. In all three series the upper limit to the linear portion of the correlation corresponded to the homolog whose GC retention time was ca 15 min under the conditions used; a high injection port temperature was found to be the most critical factor in extending the linear range of the correlation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyethyleneglycol of molecular weight 6000 was treated with 4-phenoxy-3,5-dinitrobenzoyl chloride in warm toluene. The product of this reaction is a white crystalline solid containing 0.1-0.2 mmol of labile phenoxy groups per gram of polymer derivative. In aqueous buffers of pH 7, the phenoxydinitrobenzoyl polymer reacts rapidly with side-chain sulfhydryl groups of cysteine, but very slowly with other functional groups found in polypeptides, yielding peptide-polymer compounds in which the peptide and polymer are linked by a thiol-sensitive dinitrophenylene bridge. Both small synthetic peptides and the B-chain of bovine insulin thus linked to polyethylene glycol are soluble in water and in some organic solvents. An arginine-containing peptide bound to the polymer was hydrolyzed by trypsin at the arginyl bond, indicating that the linear polyethyleneglycol support does not restrict access of enzymes to bound peptides. Release of peptides from the polymer is rapidly accomplished by treatment with thiols at pH 7 in aqueous solutions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 526-529 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In Lösungen verschiedener Harze mit unterschiedlicher Konzentration wurde die Ultraschallgeschwindigkeit gemessen. Die erhaltenen Ergebnisse waren Grundlage zur Berechnung verschiedener physikalischer Parameter der Harzlösungen.
    Notes: In solutions of different resins the ultrasonic velocity was measured at different concentrations. The obtained results were used to evaluate some physical parameters of the resin solutions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 134-135 
    ISSN: 0323-7648
    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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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 41 (1990), S. 51-53 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die dielektrischen Eigenschaften von drei Epoxidharzen wurden in Abhängigkeit von der Frequenz und der Temperatur untersucht. Die Gleichstromleitfähigkeit der Proben wurde bei unterschiedlichen Temperaturen gemessen. Ein Vergleich der Ergebnisse zeigt, daß die dielektrischen Eigenschaften von der Epoxidzahl abhängen, während die Gleichstromleitfähigkeit hauptsächlich von der Molekülmasse der Epoxidharze bestimmt wird.
    Notes: The dielectric properties of three epoxy resins have been studied as a function of frequency and temperature. The de conductivity of the samples was measured at different temperatures. A comparison of the results shows that the dielectric properties are dependent on the epoxide value, while the de conductivity depends mainly on the molecular weight of the epoxy resins.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 473-475 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Röntgenstreuung von Amino-, Epoxy-, Alkyd- und Esterharzen wurde untersucht. Aus dem diffusen Halo wurde ein effektiver Abstand der Polymerketten berechnet. Mit Hilfe der von Boyer und Miller vorgeschlagenen empirischen Korrelationen wurde die Querschnittsfläche der Kettenmoleküle ermittelt, und daraus wurden die Zahl der Atome zwischen zwei Verknüpfungen, der Steifheitsparameter der Kette und die isotherme Kompressibilität abgeschätzt.
    Notes: The X-ray diffraction of amino, epoxy, alkyd, and ester gum resins was investigated. The diffraction halo was used to compute an effective distance value in the polymers. With the help of the empirical correlation graphs suggested by Boyer and Miller the cross-sectional area of the chain molecules was evaluated, and from that the number of chain atoms per entanglement, the stiffness parameters of the chain, and the isothermal compressibility were estimated.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 42 (1991), S. 668-670 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ein Verfahren zur Synthese eines Triglycidylisocyanuratharzes in guter Ausbeute und Reinheit ausgehend von heterocyclischer Cyanursäure wird beschrieben. Reinheit und Struktur des Harzes werden durch Schmelzpunktbestimmung. IR- und NMR-Spektroskopie, Elementaranalyse sowie Bestimmung des Epoxidäquivalentes bestätigt.
    Notes: A procedure is described to synthesize heterocyclic cyanuric acid based triglycidyl isocyanurate resin in good yield and purity. The purity and configuration of the resin were confirmed by determination of the melting point, IR and NMR spectroscopy, elemental analysis, and epoxide equivalent.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 10 (1981), S. 103-105 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Generalized phase matching conditions for the four-wave mixing process of coherent anti-Stokes Raman scattering (CARS) is examined. The use of three incident laser beams leads to better spectral and angular separation of the CARS signal than is possible in standard two beam CARS experiments. Furthermore, large background reduction is shown possible through the use of three frequencies. Special attention is paid to the universal phase matching geometry where two of the laser beams counterpropagate (COPCARS). Experimental results obtained with the COPCARS are presented. The technique is especially useful for studying small frequency shifts such as those associated with rotational Raman, Brillouin and Rayleigh wing scatterings.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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