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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 108 (1977), S. 1163-1165 
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Fluorenone was nitrated using cupric nitrate in the presence of acetic acid and acetic anhydride. Nitration was carried out under mild conditions; 2-nitrofluorenone was obtained as the only product.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 89-96 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In the present work oxygen index (OI) measurements and thermogravimetric analysis (TG) for a series of polyurethanes based on diols and isocyanate were conducted. It was found that a correlation exists between some of the thermal degradation parameters obtained from TG and OI-values. Analysis of experimental results confirms that the amount of mass loss at 250°C is directly proportional to the OI-value. It was also found that the logarithmic temperatures of maximal decomposition rates are directly proportional to the OI-values.
    Notes: In der vorliegenden Arbeit wurden für eine Serie von Polyurethanen auf der Basis von Diol und Isocyanat der Sauerstoffindex (SI) gemessen und die thermische Zersetzung mittels thermogravimetrischer Analyse (TG) untersucht. Dabei wurde ein Zusammenhang zwischen einigen Parametern der thermischen Zersetzung und den SI-Werten gefunden. Die Auswertung der experimentellen Ergebnisse zeigte, daß die Höhe des Massenverlustes bei 250°C und die SI-Werte direkt proportional zueinander sind. Derselbe Zusammenhang besteht auch zwischen dem Logarithmus der Temperatur bei der maximalen Zersetzungsgeschwindigkeit und den SI-Werten.
    Additional Material: 5 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 181 (1980), S. 1209-1213 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Spectrophotometric studies in the UV region were carried out for a series of chlorine and bromine derivatives of N-ethylcarbazole and poly(N-vinylcarbazole). All the examined polymers, in the whole spectral range, exhibit considerably less absorptivity than their low molecular models, i.e. ethylcarbazoles. Absorption bands of the polymers are shifted, in comparison to the respective absorption bands of halogenethylcarbazoles, towards shorter wavelenghts. Halogen substituents in the carbazole ring reduce the transfer energy π → π*. This bathochromic effect is especially observable for low-energy bands 1La and 1Lb, and it was noticed that the bromine substituent exerts more influence than the chlorine substituent.
    Additional Material: 3 Tab.
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 179 (1978), S. 2969-2975 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Absorption and luminescence spectra of halogen derivatives of poly(N-vinylcarbazole) have been investigated in solution and solid films. The emission spectra in solution exhibit excimer phosphorescence only, whereas solid film spectra show excimer fluorescence only. Changes in the character of emission spectra on passing from solution to solid film are discussed.
    Additional Material: 5 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 1991-1999 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The absorption spectra of the complexes of tetracyanoethylene with poly(N-vinylcarbazole), poly(N-vinyl-3-chlorocarbazole), and poly(N-vinyl-3,6-dichlorocarbazole) were investigated in the visible range as a function of the pressure. The degree of complexation expressed by the equilibrium constant, the oscillator strength, and the excitation energy were determined. A significant increase of the oscillator strength was observed, when the pressure increases, this being in agreement with Mulliken's theory. With increasing pressure the absorption maximum of the CT complex was shifted towards the infra-red. Two peaks were found as a consequence of a splitting of the absorption band under the influence of pressure. This effect is discussed in terms of the existence of orientational isomers. An influence of the substituents (chlorine) in 3-and 3,6-positions of carbazole on the spectral properties of the complexes was found.
    Additional Material: 7 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 192 (1991), S. 27-34 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poröse Copolymere aus N-Vinylcarbazol (NVC) und Divinylbenzol wurden untersucht. Die Copolymeren wurden durch Suspensionspolymerisation in Gegenwart von gut (Isopentanol und Toluol) und schlecht (Dodecan und Toluol) lösenden Mischungen organischer Lösungsmittel hergestellt.Die übermolekulare Struktur der Copolymeren hängt nicht nur vom Vernetzungsgrad ab, sondern auch von der thermodynamischen Qualität der Lösungsmittel. In guten Lösungsmitteln wurden bei geringem Vernetzungsgrad (〈20% DVB) porösgelartige Copolymere gebildet.Die Sorptionseigenschaften der porösen NVC-DVB-Copolymeren für p-Nitrophenol sind ähnlich denen von Acrylnitril-DVB-Copolymeren.
    Notes: Porous copolymers of N-vinylcarbazole (NVC) and divinylbenzene (DVB) of different composition (crosslinking degree) have been studied. The copolymers were obtained by suspension polymerization carried out in the presence of diluents, mixtures of ‘good’ (isopentanol and toluene) and ‘bad’ solvents (dodecane and toluene).The supermolecular structure of the copolymers was found to depend not only on the crosslinking degree, but on the thermodynamic quality of diluents. In the presence of good solvents, copolymers of the porous-gel type were formed at relatively small crosslinking degree (〈20% DVB).Sorption properties of porous NVC-DVB copolymers with respect to p-nitrophenol were found to be similar to those of acrylonitrile-DVB copolymers.
    Additional Material: 1 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 251 (1997), S. 1-12 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zur Synthese von niedermolekularen Epoxidharzen aus Bisphenol A und Epichlorhydrin wurden quaternäre Ammoniumsalze, Sulfoxide und Sulfolane als Katalysatoren eingesetzt. Die Reaktion wurde bei Raumtemperatur in einem polaren Lösungsmittel durchgeführt, und die Bildung der Epoxidharze unter den Bedingungen der Phasentransferkatalyse wurde untersucht. Abhängig von Katalysatortyp und Reaktionsbedingungen wurden Epoxidharze mit unterschiedlichen Epoxidäquivalenten erhalten. Die Anwendung der Phasentransferkatalyse erlaubte die Herstellung von Epoxidharzen in einem einstufigen Prozeß unter milden Bedingungen und mit einer geringeren Menge an Epichlorhydrin. Zur Synthese von niedermolekularen Epoxidharzen erwies sich das System Dichlormethan/NaOHaq in Gegenwart von quaternären Ammoniumsalzen, Sulfoxiden oder Sulfolanen als sehr geeignet.
    Notes: Quaternary ammonium salts, sulfoxides and sulfoianes were used as catalysts in the syntheses of low-molecular-weight epoxy resins from bisphenol A and epichlorohydrin. The reaction was carried out in a polar organic solvent at room temperature. The process of synthesis of epoxy resins under phase transfer catalysis (PTC) conditions was studied. Depending on the type of the catalyst and on the reaction conditions epoxy resins with different epoxy group equivalents were obtained. Application of the PTC conditions enabled the synthesis of epoxy resins in a singlestage process, under mild conditions and with a lower amount of epichlorohydrin. It was observed that the system dichloromethane/NaOHaq in the presence of quaternary ammonium salts or sulfoxides or sulfolanes is very convenient in the synthesis of low-molecular-weight epoxy resins.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 57 (1995), S. 1025-1030 
    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: Blends containing poly(vinyl chloride) and 9-(2,3-epoxypropane)carbazole in different weight ratios were subjected to investigations using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The effect of additive on the polymer degradation process was studied. It was found that 9-(2,3-epoxypropane)carbazole causes an increase in the onset temperature of hydrogen chloride emission by about 20-25°C. Finally, the mechanisms of stabilization were proposed. © 1995 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 46 (1992), S. 2139-2146 
    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: On the basis of kinetic studies of noncatalyzed synthesis of carbamates in chlorobenzene solution, a kinetic model of polyurethane synthesis has been proposed. The model was built on a set of elementary, sequential - parallel reactions between functional groups of the main reagents involved in polyurethane synthesis. The assumption that reactivity of reagents did not depend of their mol wt allowed simulation of the kinetics of formation of allophanate branches for various process parameters. It has been found that the process temperature and initial ratio of reagents are of primary importance. A set of equations, describing the synthesis of linear polyurethanes, has been derived. The equations afford calculation of the degree of polymer chain branching and their application yields results similar to those obtained by the more general method based on numerical solution of the differential equations involved. Advantages resulting from the mathematical modeling of the process kinetics have been pointed out. © 1992 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 331 (1989), S. 145-148 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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