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  • Polymer and Materials Science  (10)
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  • 1
    Electronic Resource
    Electronic Resource
    Specific features of styrene polymerization on 1,3-bis(1-lithio-1-methylhexyl)benzene in the presence of tetrahydrofuran (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 1623-1628 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Basic feature of styrene polymerization under the action of 1,3-bis(1-lithio-1-methylhexyl)-benzene (1) in the presence of tetrahydrofuran were studied. UV spectra of 1 and dilithiumpolystyrene in a benzene solution with an without THF were investigated. A comparison of the results of the UV spectra with the data of cryoscopy and viscometric measurements of “living” and deactivated polystyrene allows the conclusion that polystyrene chains propagating on the dilithium catalyst are in monomeric form.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021830704
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  • 2
    Electronic Resource
    Electronic Resource
    Structure and properties of copolymers of vinylcyclohexane and α-methylvinylcyclohexane with acrylonitrile (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 2989-2997 
    Details
    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: A study has been made of the structure and properties of alternating equimolar and random copolymers of vinylcyclohexanne and α-methylvinylcyclohexane with acrylonitrile using infrared and 1H-NMR spectroscopy methods, as well as x-ray diffraction and differential thermal analyses. The spectral methods allowed an estimation of the composition and distribution of comonomer units in the copolymer macrochains. The thermal stability of alternating copolymers was found to be higher than that of polyacrylonitrile. Alternating and random copolymers are amorphous products with various dimensions of crystallites. Information on the molecular motion intensity and temperatures of structural transitions in copolymer macrochains was obtained by the spin-probe technique.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070231017
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  • 3
    Electronic Resource
    Electronic Resource
    Copolymers of vinylcyclohexane with styrene: Peculiarity of thermal behavior, parameters of crystal structure, and structural transitions (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 755-764 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal behavior, the parameters of crystal structure, and the structural transitions of copolymers of vinylcyclohexane with styrene were studied. Heating in air of the copolymers and of mechanical mixtures of homopolymers results in thermooxidative destruction. For all samples, the oxidation starts at 210-220°C. The antioxidant effect on thermal stability of copolymers was studied. Differential thermal analysis (DTA) data were used to determine the melting points of homopolymers and crystal copolymers. The method of x-ray diffraction on large scattering angles was used to determine the dimensions and type of unit cells, the degree of crystallinity, the dimensions of the coherent scattering regions (the dimensions of crystallites) of copolymers of various compositions, and to compare them to the parameters of the structure of polyvinylcyclohexane and polystyrene. Information on molecular motion intensity and structural transitions in homopolymers and copolymers with changing temperature was obtained by the spin-probe technique.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150321
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  • 4
    Electronic Resource
    Electronic Resource
    Copolymerization of vinyl cyclohexane and α-methyl vinyl cyclohexane with acrylonitrile (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 3233-3248 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymerization of vinyl cyclohexane and α-methyl vinyl cyclohexane with acrylonitrile in the presence of a complexing agent AlEtCl2 results in the formation of alternate copolymers. In the copolymerization of vinyl cyclohexane with acrylonitrile the copolymer composition depends on the ratio of acrylonitrile to AlEtCl2. If this ratio is unity, alternating copolymers of the composition 1:1 are formed; with a ratio greater than unity statistical copolymers that contain more than 50% acrylonitrile units are produced. The 1H-NMR spectroscopy measurements indicate that the interaction between the comonomers and the complexing agent leads to the formation of ternary donor-acceptor complexes of equimolar composition. The equilibrium constants of these complexes at -60°C have been determined. The effects of temperature, nature of solvent and dilution on the yield, and composition of the copolymers of vinyl cyclohexane with acrylonitrile formed have been studied. By lowering the temperature the yield of copolymers increases but their composition remains equimolar. An increase in the polarity of the medium results in an increase in copolymer yield, whereas the yield decreases if the reaction is conducted in a donor-solvent medium. Dilution of the reaction mixture disrupts the alternation of units in the macrochain of copolymers. The kinetic pecularities of copolymerization have been investigated. The linear dependence of the copolymerization rate on the product of comonomer concentration is observed. The rate of copolymerization is proportional to the square root of the incident light intensity. Various additions of radical type and irradiation accelerate the process of copolymerization. The mechanism of alternating copolymerization of vinyl cyclohexane monomers with acrylonitrile in the presence of AlEtCl2 is discussed in terms of homopolymerization of the comonomer complex.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170161217
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  • 5
    Electronic Resource
    Electronic Resource
    Cationic polymerization of isobutylene initiated by Friedel-Crafts catalysts. Peculiarities of the initiation reaction in a non-polar medium (1989)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 407-409 
    Details
    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: Der Einfluß von Wasser auf die kationische Polymerisation von Isobuten durch AlEtCl2 in n-Heptan wurde untersucht. Vollständige Inhibierung der Polymerisation wurde bei [H2O] ≦ 10-5mol/1 erreicht. Langsame Polymerisation mit einer Induktionszeit wurde beim Verhältnis [H2O]/AlEtCl2 ≦ 1 gefunden. Mit Hilfe von 2,6-DTBP und O2 wurden zwei Initiierungsmechanismen gefunden, die gleichzeitig ablaufen: ein cokatalytischer Mechanismus und die direkte Katalyse durch Einelektronentransfer von Isobuten zu AlEtCl2. Die Möglichkeit zur Steuerung des Mechanismus wird aufgezeigt.
    Notes: The effect of water on the cationic polymerization of isobutylene by AlEtCl2 in n-heptane has been studied. The condition of complete polymerization inhibition is attained at [H2O] ≦ 10-5mol/1. Slow polymerization with an induction period is detected at [H2O]/[AlEtCl2] ≦ 1. By means of 2,6-DTBP and O2 two mechanisms of initiation proceeding at the same time have been found: a cocatalytic mechanism and direct catalysis by means of a single-electron transfer from isobutylene to AlEtCl2. The possibility of the control of the reaction is shown.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1989.010400611
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  • 6
    Electronic Resource
    Electronic Resource
    Catalytic degradation of polyolefines under the action of Friedel-Crafts catalysts in solution. 1. Some new features of catalytic degradation of poly(isobutylene) (1990)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 41 (1990), S. 226-229 
    Details
    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: Der katalytische Abbau von Poly(isobuten) bei Einwirkung von AlBr3 und AlEtCl2 in aliphatischen Lösungsmitteln wurde im Temperaturbereich von 20 bis 60°C untersucht. Die kinetischen Besonderheiten des Prozesses wurden festigestellt. 2,6-Di-Tert-Butylpyridin erwies sich als indifferent gegenüber dem Abbauprozeß, wogegen O2, p-Benzochinon und Tetracyanethylen einen Inhibitoreffekt zeigten. Auf der Grundlage von ESR-Untersuchungen wurde die Möglichkeit eines radikalischen Mechanismus der Abbaureaktion aufgezeigt.
    Notes: The catalytic degradation of poly(isobutylene) under the action of AlBr3 and AlEtCl2 in aliphatic solvents was studied at 20 to 60°C, and the kinetic features of the process were established. The investigation of the influence of 2,6-di-tertbutylpyridine showed its indifference towards the degradation process, while O2, p-benzoquinone, and tetracyanoethylene have an inhibiting effect. On the basis of EPR studies the posibility of a radical chain mechanism of the degradation reaction could be shown.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1990.010410408
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of crystalline polyvinylcyclohexane (1961)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 52 (1961), S. 199-204 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The least known field of stereospecific polymerization is the polymerization of vinylcycloalkanes. At the same time polyvinylalkanes and especially polyvinylcycloalkanes may be of considerable interest as a new class of crystalline polyvinyl compounds. With this in mind the synthesis of polyvinylcyclohexane has been carried out and its properties have been investigated. Polymerization of vinylcyclohexane takes place in the presence of titanium tetrachloride and isobutylaluminum or of chromium oxides on aluminum silicate. The polymer obtained with different catalysts and under varying conditions (temperature, solvent, catalyst concentration, etc.) according to x-ray data has a high degree of crystallinity. The melting point is 325° and the intrinsic viscosity from 0.5 to 1.5. A characteristic feature is its good solubility in naphthenic and aromatic hydrocarbons. The structure of the polymer has been established and thermomechanical curves have been determined for polymers obtained on various catalysts.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1961.1205215726
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  • 8
    Electronic Resource
    Electronic Resource
    Preparation of polymeric materials with semiconductor propertiesPresented at the IUPAC International Symposium on Macromolecular Chemistry, Moscow, June 1960. (1961)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 54 (1961), S. 621-626 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thermal treatment of polyacrylonitrile synthesized by means of ionic polymerization, radiation polymerization, or redox initiation yielded substances giving signals in the EPR spectrum and possessing semiconductor properties. From the temperature dependence of the electroconductivity the activation energy was determined, and from the data on the EPR spectra the number of unpaired electrons (1018-5 × 1019/g.) was calculated. The thermoelectromotive force was determined and the existence of a Hall effect established. Addition of copper, iron, and chromium ions to the initial polymer lowers the activation energy and increases the width of the EPR signal. On dehydrobromination of natural rubber bromides and dehydrochlorination of polyvinyl chloride, conjugated double bond polymers were obtained, and their electrical properties were determined. Semiconductor properties were found in condensation products of phthalic anhydride with hydroquinone and the activation energy of these compounds was determined.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1961.1205416025
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  • 9
    Electronic Resource
    Electronic Resource
    On the question of applying chromium oxide and molybdenum oxide catalysts to obtain crystalline poly-α-olefins (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 34 (1959), S. 129-137 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This article gives experimental data concerning the dependence of polymerization efficiency of chromium oxide catalyst upon the methods of preparation and reports on the character of the polymerization efficiency. The polyethylene and polypropylene obtained in this process of polymerization is characterized by high quality. Besides chromium oxide catalyst, molybdenum oxide catalyst with added lithium hydride was studied.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203412709
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  • 10
    Electronic Resource
    Electronic Resource
    Catalytic degradation of polyolefines under the action of friedel-crafts catalysts in solution. 2. Investigation of structural pecularities of degraded poly(isobutene) by low-temperature calorimetry and 13C-NMRPart 1: see [3] (1992)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 43 (1992), S. 102-106 
    Details
    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 Temperaturabhängigkeit der spezifischen Wärme von durch Einwirkung starker Lewissäuren abgebautem Poly(isobuten) wurde untersucht. Aus den berechneten thermodynamischen Parametern wurden Schlußfolgerungen über strukturelle Umwandlungen der Makromoleküle bei katalytischen Abbau gezogen. Mittels 13C-NMR wurde die Bildung verzweigter Makromoleküle nachgewiesen. Auf der Grundlage dieser Ergebnisse wurde ein Abbaumechanismus für Poly(isobuten) vorgeschlagen.
    Notes: The temperature dependence of specific heat of poly(isobutene) degraded under the action of strong Lewis acids has been investigated. From the calculated thermodynamic parameters have been drawn conclusions on the structural conversions of the macromolecules in the process of catalytic degradation. By means of 13C-NMR the formation of branched macromolecules was shown. On the basis of the results a degradation mechanism for poly(isobutene) is suggested.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1992.010430210
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