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  • 1
    Electronic Resource
    Electronic Resource
    Monte-Carlo-simulation for the structure of copolymer molecules of chemical inhomogeneity of second typeDedicated to Professor Dr. G. Manecke on the occasion of his 70th birthday (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 2467-2479 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A method is discussed for Monte-Carlo-simulation of copolymer molecules with chemical inhomogeneity of the second type. The copolymer molecules are formed by a polyreaction with monomer addition without chain termination, e.g. in case of an anionic “living” polymerization. The reliability of the method was statistically tested with examples. The method allows a clear presentation of the copolymer molecules mentioned in the paper.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021881021
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Experimenteller nachweis des molekulardispersen charakters der mischung von zwei polymeren und bestimmung des chemischen potentials in diesen mischungenHerrn Prof. Dr. G. V. Schulz zum 70. Geburtstag gewidmet (1976)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 177 (1976), S. 1145-1160 
    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: With the aid of small-angle neutron scattering the molecularly disperse character of a clear mixture of two polymers in the absence of a low molecular weight compound is proved in one case and disproved in the other. If the mixture is molecularly disperse the chemical potential and the coil dimensions can be determined. Poly(methyl methacrylate) and styrene-acrylonitrile copolymers for certain compositions of the copolymer form molecularly disperse mixtures. They are exothermic, have a negative excess entropy of mixing and the coils are expanded as compared with the unperturbed coil dimensions. The theory of solubility parameters of Hildebrand and Scott enables one to find the miscible system, but the experimental second osmotic virial coefficients differ by an order of magnitude from those which could be estimated from this theory.
    Notes: Mit Hilfe der Neutronenkleinwinkelstreuung wird der molekulardisperse Charakter einer glasklaren Mischung von zwei Polymeren bei Abwesenheit eines niedermolekularen Lösungsmittels in einem Fall nachgewiesen, im anderen widerlegt. Falls eine molekulardisperse Mischung vorliegt, können das chemische Potential und die Knäueldimensionen bestimmt werden. Polymethylmethacrylat und Styrol-Acrylnitril-Copolymere bilden für gewisse Zusammensetzungen des Copolymeren molekulardisperse Mischungen. Sie sind exotherm, besitzen eine negative Exzeßentropie und die Molekülknäuel sind gegenüber den ungestörten Knäueldimensionen expandiert. Die Theorie der Löslichkeitsparameter von Hildebrand und Scott ermöglichte zwar die Auffindung des mischbaren Systems, aber die gemessenen zweiten osmotischen Virialkoeffizienten sind in der Größenordnung verschieden von denen, die nach dieser Theorie vorausberechnet werden können.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1976.021770415
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  • 3
    Electronic Resource
    Electronic Resource
    Untersuchungen zur thermodynamik und konformation von makromolekülen in polymermischungen in der nähe von entmischungspunkten durch neutronenbeugungHerrn Prof. Dr. H. Pommer zum 60. Geburtstag gewidmet (1980)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 181 (1980), S. 1655-1672 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure and the thermodynamics of polymer blends made from two poly(styrene/acrylonitrile) copolymers with a different ratio of styrene/acrylonitrile are investigated by neutron scattering. These systems are endothermic, exhibit a positive value for the Huggins parameter χ and show phase separation at sufficiently large molecular weights. The results are in good agreement with the corresponding states theory of Prigogine and Patterson. Other polymer blends are exothermic, exhibit negative χ-values and are compatible even for infinitely large molecular weights. In these cases one can adapt the theoretical equations to the experiments by the introduction of a suitable parameter for an exothermic contact energy. This is shown for blends from poly(methyl methacrylate) and poly(styrene/acrylonitrile).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1980.021810810
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  • 4
    Electronic Resource
    Electronic Resource
    Versuche zur copolymerisation deuterierter monomerer copolymerisation styrol/deuterostyrol und methylmethacrylat/deuteromethylmethacrylatHerrn Prof. Dr. Dres. h. c. G. V. Schulz zum 75. Geburtstag gewidmet (1981)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 182 (1981), S. 2505-2516 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In free radical copolymerization of styrene with completely deuterated styrene and methyl methacrylate with completely deuterated methyl methacrylate no isotope effects upon the copolymerization parameters were observed. However, isotope effects were found in the rates of copolymerization Rp. In the case of styrene Rp decreases monotonically from a higher level for the deuterated monomer to a lower level for the [1H]-monomer. For the case of methyl methacrylate Rp again is higher for the deuterated monomer than for the [1H]-monomer, but there is a minimum in the curve Rp vs. monomer mixture composition.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1981.021820913
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  • 5
    Electronic Resource
    Electronic Resource
    Investigation of exothermic polymer blends by neutron scatteringDedicated to Professor Dr. O. Kratky on the occasion of his 80th birthday (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 129-156 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Provided a polymer is soluble, i. e., molecularly dispersed in another polymer irrespective of the molecular weight of the components, the solution is exothermic. By increasing the temperature two effects, both unfavourable to mixing become larger: (i) the excess entropy of mixing caused by contact interaction and (ii) the total effect from the difference of the free volumes of the pure components. So, an upper miscibility gap occurs. The thermodynamic properties of the mixture cannot be derived from the properties of the pure components. They can be described by the corresponding states theory of Prigogine, Flory, and Patterson with suitable values for the contact energy and contact entropy parameters X12 and Q12. The temperature of separation can be predicted from measurements on the mixture at low temperatures.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850113
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  • 6
    Electronic Resource
    Electronic Resource
    Polymerlegierungen - Struktur, Morphologie, EigenschaftenProfessor Horst Pommer zum 60. Geburtstag gewidmet (1979)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 91 (1979), S. 286-309 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Forderung nach neuen Eigenschaften polymerer Werkstoffe wird zunehmend durch den Verbund vorhandener Polymere erfüllt; die Synthese neuer Monomere ist zurückgetreten. Die Verbunde - „Polymerlegierungen“ - sind durch chemischen Aufbau, Konformation der Kettenmoleküle und den als Morphologie bezeichneten Ordnungszustand im übermolekularen Bereich charakterisiert. Typisch ist Mehrphasigkeit, die die makroskopischen Eigenschaften entscheidend beeinflußt. Die Morphologie mehrphasiger Polymerlegierungen kann beim Vermischen von Homopolymerisaten in der Schmelze oder als Dispersionen nur bedingt über den chemischen Aufbau der Komponenten gesteuert werden. Durch Pfropfcopolymerisation läßt sich die Morphologie bei vorgegebener chemischer Zusammensetzung dagegen gezielt einstellen. Unter speziellen Bedingungen werden auch transparente zweiphasige Polymerlegierungen erhalten. Der Spannungsabbau ohne Bruch bei mechanischer Belastung mehrphasiger Verbunde wird modellmäßig behandelt. Bestimmte Eigenschaftskombinationen wie Härte/Zähigkeit sind an die Koexistenz disperser und kohärenter Phasen gebunden. Auf die Entmischungsphänomene werden die gleichgewichtsthermodynamischen Kriterien für flüssige Mischungen angewendet. Die Kettenkonformation im festen Zustand ist in den letzten Jahren durch Neutronenstreuung experimentell zugänglich geworden.
    Additional Material: 39 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19790910406
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  • 7
    Electronic Resource
    Electronic Resource
    Polymer Alloys - Their Structure, Morphology, and PropertiesDedicated to Professor Horst Pommer on the occasion of his 60th birthday (1979)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 18 (1979), S. 273-295 
    Details
    ISSN: 0570-0833
    Keywords: Polymer alloys ; Polyblends ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymeric materials with novel properties for new technological applications are increasingly obtained by combining existing polymers, while the synthesis of new monomers has receded into the background. These polymer combinations or “alloys” (polyblends) are characterized by their chemical composition, the conformation of the chain molecules, and the morphology, i.e. the state of order at supramolecular level. Multiphase constitution is a typical characteristic of these substances, with a decisive influence on their macroscopic properties. The morphology of multiphase polymer alloys can be controlled to a limited extent via the chemical composition of their components when homopolymers are mixed in the melt or as dispersions. Graft copolymerization, on the other hand, makes it possible to achieve the desired morphology at a given chemical composition. Furthermore, transprent two-phase polymer alloys can be obtained under certain conditions. In multiphase polymers the reduction of stress without fracture, caused by mechanical loading will be treated using models. Certain combinations of properties such as hardness and toughness are connected with the coexistence of disperse and continuous phases. Equilibrium thermodynamical criteria for liquid mixtures wil be used to explain demixing phenomena in polymers. In the last few years it has become possible to determine the chain conformation experimentally using neutron scattering.
    Additional Material: 39 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.197902731
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