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  • 1
    Electronic Resource
    Electronic Resource
    Polymerization of methylmethacrylate initiated by hydrogenation catalysts (1967)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 104 (1967), S. 254-262 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: RANEY-Metalle (Ni, Fe, Co), URUSHIBARA-Metalle (Ni, Co) und ULLMANN-Kupfer können die Polymerisation von Methylmethacrylat einleiten, wobei die Anwesenheit von Diaminen, Diolen oder organischen Halogenverbindungen die Reaktivität der genannten Metalle erhöht.In Gegenwart von CCl4 ist die Reaktionsgeschwindigkeit (Rp) einerseits proportional der Quadratwurzel der Menge der Metalle und des CCl4, andererseits der ersten Potenz der Konzentration des Monomeren; jedoch wird Rp konstant und unabhängig von der Konzentration des CCl4, wenn dieser in großem Überschuß vorliegt.Es wird geschlossen, daß die vorliegende Polymerisation über freie Radikale verläuft. Es wird angenommen, daß ein nullwertiges Metallatom bei der Initiierung beteiligt ist, wobei eine Komplexbildung zwischen Metall und CCl4 erfolgt.
    Notes: RANEY metals (Ni, Fe, Co), URUSHIBARA metals (Ni, Co) and ULIMANN cu initiate the polymerization of methylmethacrylate. Diamines, diols or organic halides enhance their reactivity.In the presence of CCl4, the polymerization rate (Rp) is proportional to the square root of the amount of both metals and CCl4, and to the first power of the monomer concentration, but Rp becomes constant and independent of the concentration of CCl4 when there is a great excess of CCl4.We concluded that this polymerization follows the free radical mechanism and the participation of a zero-valent metal atom in the initiation reaction including complex formation between metal and CCL4 is suggested.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1967.021040126
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  • 2
    Electronic Resource
    Electronic Resource
    Participation of the depropagation reaction in the cationic copolymerization of 3.3-bischloromethyl oxacyclobutane and tetrahydrofuran (1968)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 117 (1968), S. 242-255 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Für die kationische Copolymerisation von 3.3-Bischloromethyl-oxacyclobutan und Tetrahydrofuran wurde eine Gleichung, für die Zusammensetzung des Copolymeren, bei der auch die Depolymerisation berücksichtigt wurde, abgeleitet und angewendet. Der mit steigender Polymerisationstemperatur oder mit Abfall der Monomerenkonzentration beobachtete Abfall der Anzahl der Tetrahydrofuraneinheiten, die in das Copolymere eingebaut werden, wird durch die Gleichung gut erklärt. Es wurden auch Unterschiede in der Wirksamkeit der Katalysatorsysteme BF3 · (C2H5)2O, (C2H5)3OBF4, C6H5N2PF6 und Al(C2H5)3—H2O beobachtet.
    Notes: A copolymer composition equation including the depropagation reaction was derived and applied to the cationic copolymerization of 3.3-bischloromethyl oxacyclobutane and tetrahydrofuran. The observed decrease of the number of tetrahydrofuran units incoroporated in the copolymer with increase of the polymerization temperature or with decease of the monomer concentration was well explained by the equation. Differences between the catalyst systems, BF3·Et2O, Et3OBF4,PhN2PF6, and AlEt3—H2O were also observed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1968.021170123
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  • 3
    Electronic Resource
    Electronic Resource
    Relation between impact strength and dynamic mechanical properties of plasticsProd. No. 1574 (1967)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 1661-1665 
    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 simple theory is developed which correlates the Izod impact strength of polymers with (G′100-G′300)2/G′100, where G′100 and G′300 are dynamic shear moduli at 100°K. and 300°K., respectively. The theory assumes the Maxwell element for the material and the fracture time smaller than the relaxation time. The theory is verified by experimental data for numerous polymers. Another approach which correlates the impact strength with the integrated loss factor from 0 to 300°K. is also proved valid.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1967.070110906
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  • 4
    Electronic Resource
    Electronic Resource
    Equilibrium polymerization of 1.3-dioxolane (1968)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 114 (1968), S. 146-154 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Gleichgewichtspolymerisation von 1.3-Dioxolan und einiger abgeleiteter cyclischer Formale wurde unter Anwendung des Bortrifluorid/Äthyläther-Komplexes als Katalysator in benzolischer Läsung untersucht. Aus der Beziehung zwischen Gleichgewichtskon-zentration des Monomeren und Polymerisationstemperatur wurden die thermodynamischen Polymerisationsparameter wie folgt ermittelt: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{*{20}c} {1.3 - {\rm dioxolane }\Delta {\rm H}_{\rm p} = - 3,6 \pm 0.6\ {\rm kcal}/{\rm mole},{\rm }\Delta {\rm S}_{\rm p}^{\rm o} = - 14 \pm 2\ {\rm cal}/{\rm mol}.{\rm grad}.} \hfill \\ {1.3 - {\rm dioxolane }\Delta {\rm H}_{\rm p} = - 3,2 \pm 0.5\ {\rm kcal}/{\rm mole},{\rm }\Delta {\rm S}_{\rm p}^{\rm o} = - 9.3 \pm 1.4\ {\rm cal}/{\rm mol}.{\rm gard}.} \hfill \\ {1.3.6 - {\rm dioxolane }\Delta {\rm H}_{\rm p} = - 5,3 \pm 0.8\ {\rm kcal}/{\rm mole},{\rm }\Delta {\rm S}_{\rm p}^{\rm o} = - 9.3 \pm 1.4\ {\rm cal}/{\rm mol}.{\rm deg}.} \hfill \\ \end{array}$$\end{document}
    Notes: Equilibriurn polymerizations of 1.3-dioxolane and some related cyclic formals have been studied in benzene solution by using boron fluoride ethyl ether complex as a catalyst. From the relation between equilibrium monomer concentration and polymerization temperature, the thermodynamic parameters of the polymerization of these cyclic formals were evaluated as follows: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{*{20}c} {1.3 - {\rm dioxolane }\Delta {\rm H}_{\rm p} = - 3.6 \pm 0.6\ {\rm kcal}/{\rm mole},{\rm }\Delta {\rm S}_{\rm p}^{\rm o} = - 14 \pm 2\ {\rm cal}/{\rm mol}.\deg .} \hfill \\ {1.3 - {\rm dioxolane }\Delta {\rm H}_{\rm p} = - 3.2 \pm 0.5\ {\rm kcal}/{\rm mole},{\rm }\Delta {\rm S}_{\rm p}^{\rm o} = - 9.3 \pm 1.4\ {\rm cal}/{\rm mol}.\deg .} \hfill \\ {1.3.6 - {\rm dioxolane }\Delta {\rm H}_{\rm p} = - 5.3 \pm 0.8\ {\rm kcal}/{\rm mole},{\rm }\Delta {\rm S}_{\rm p}^{\rm o} = - 9.3 \pm 1.4\ {\rm cal}/{\rm mol}.\deg .} \hfill \\ \end{array}$$\end{document}
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1968.021140111
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  • 5
    Electronic Resource
    Electronic Resource
    Kinetic studies on the polymerization of 1.3-dioxolane catalyzed by triethyl oxonium tetrafluoroborate (1968)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 117 (1968), S. 256-264 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Kinetik der Polymerisation von 1.3-Dioxolan mit Triäthyloxoniumtetrafluorborat als Katalysator in Methylenchlorid als Lösungsmittel wurde untersucht. Der Polymerisation geht eine Induktionsperiode voraus. Ein Zusatz von Wasser verlängert die Induktionsperiode und setzt sowohl die Polymerisationsgeschwindigkeit als auch das Molekulargewicht des Polymeren herab. Die Induktionsperiode ist proportional dem reziproken Wert der Anfangskonzentration des Katalysators, aber unabhängig von der Anfangskonzentration des Monomeren. Die Induktionsperiode scheint also hauptsächlich von einer Reaktion des Katalysators mit Wasser abzuhängen. Eine annähernd lineare Abhängigkeit zwischen dem Polymerisationsgrad und dem Umsatz deutet darauf hin, daß die Polymerisation Abwesenheit von Wasser im wesentlichen ohne Abbruchs- und Übertragungsreaktionen bis zu einem Gleichgewicht verläft. In Methylenchlorid ist die Geschwindigkeitskonstan der Wachstumsreaktion bei 30°C 4,3·10-2l/mol sec.
    Notes: The kinetics of the polymerization of 1.3-dioxolane with triethyl oxonium tetrafluoroborate has been studied in methylene chloride solution. The polymerization was preceded by an induction period. The addition of water to the system prolonged the induction period and decreased both rate of polymerization and molecular weight of the polymer. The induction period was found to be proportional to reciprocal of the initial catalyst concentration but to be independent of initial monomer concentration. Therefore it would appear that the induction period is mainly due to a reaction of the catalyst with water. A near linear relationship between the degree of polymerization and the conversion suggested that the polymerization proceeds essentially without termination and chain transfer reactions to an equilibrium conversion in the absence of water. The rate constant of propagation was estimated to be 4.3·10-2l./ mole sec in methylene chloride at 30°C.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1968.021170124
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  • 6
    Electronic Resource
    Electronic Resource
    Resonance Raman spectra of 2-(2-pyridylazo)-5-diethylaminophenol and its complex at various pH values (1987)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 18 (1987), S. 205-209 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure of 2-(2-pyridylazo)-5-diethylaminophenol (PADAP) and its complex at various pH values was studied by resonance Raman spectroscopy. The spectral features are sensitive to the pH and the solvent, which can be explained in terms of azo-hydrazone tautomers. Two types of quinonoid structures are found under neutral conditions: a hydrazone structure in chloroform solution and a pyridone-like structure with an N—H bond in the pyridine ring in aqueous solution. The quinoid structure is found at both pH 0.1 and 2.3. The relationship between the structure and the absorption spectrum under neutral conditions is discussed on the basis of CNDO/2 calculations.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250180311
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  • 7
    Electronic Resource
    Electronic Resource
    Raman scattering study of CsH2PO4 (1984)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 15 (1984), S. 97-102 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman spectra of CsH2PO4 have been observed at 295 and 83 K in the frequency shift region 40-1200 cm-1. According to factor group analysis, Raman active vibrational modes at k = 0 are classified as follows; 13Ag + 8Bg in the paraelectric phase and 23A + 22B except for acoustic modes in the ferroelectric phase. No soft modes were observed in the A class modes. The frequency and the line width of one of the internal modes of the HPO42- ions were measured as a function of temperature in the scattering geometries b(cc)a* and c(bb)a*, where a* is perpendicular to the bc plane. Remarkable anisotropy was found in the temperature dependence of both the frequency and the line width. The results are discussed by considering that the phase transition is of an order-disorder type and the relaxation time of the polarization fluctuation is very long compared with the inverse of the associated phonon frequencies.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250150206
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  • 8
    Electronic Resource
    Electronic Resource
    Study of the phase transition of CsD2PO4 by Raman scattering (1985)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 16 (1985), S. 407-411 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman scattering from CsD2PO4 was observed in the paraelectric and ferroelectric phases. The line width and the frequency of one of the totally symmetric A modes were measured as a function of temperature. An anomalous change in the line width was observed and this is qualitatively discussed in relation to the frequency shift below the transition temperature.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250160609
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