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  • Electronic Resource  (75)
  • 1990-1994  (21)
  • 1980-1984  (32)
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  • Polymer and Materials Science  (75)
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  • Electronic Resource  (75)
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  • 1
    Electronic Resource
    Electronic Resource
    The free-radical terpolymerisation of ethylene, methyl acrylate and vinyl acetate at high pressure. Polymerization testsCf.13. (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 211 (1993), S. 131-140 
    Details
    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 dieser Arbeit wurde die Terpolymerisation unter Hochdruck am Beispiel des Systems Ethylen-Methylacrylate-Vinylacetat untersucht. Die Polymerisationsversuche wurden in einer kontinuierlich betriebenen Hochdruckpolymerisationsanlage durchgeführt. Zur Beurteilung der Druck- und Temperatureinflüsse auf die Reaktion wurde die Polymerisation bei zwei verschiedenen Drücken von 1900 und 1100 bar sowie Temperaturen von 180 und 230°C durchgeführt. Durch Variation der Konzentrationen der Monomeren Ethylen, Methylacrylat und Vinylacetat im Ansatz wurden Polymerisate mit unterschiedlicher Zusammensetzung erhalten. Das Konzentrationsverhältnis der Monomeren im Reaktor wurde aus der Auswaage und dem Comonomergehalt des Polymerisats sowie der Feedzusammensetzung unter Anwendung der Massenbilanz für den idealen Rührkessel berechnet. Daraus wurden die Copolymerisationsparameter der drei möglichen binären Copolymerisationen Ethylen/Methylacrylat, Ethylen/ Vinylacetat und Methylacrylat/Vinylacetat Bestimmt. Mit diesen Daten kann die Zusammensetzung eines Produkts aus der kontinuierlichen Polymerisation in einem Rührautoklaven vorausberechnet werden.
    Notes: In this study, the terpolymerisation, under high pressure, has been examined for the ethylene-methyl acrylate-vinyl acetate system. The polymerisations were carried out in a high pressure polymerisation facility designed for continuous operation. To assess the effect of pressure and temperature on the reaction, polymerisation was carried out at two different pressures of 1 900 and 1 100 bar and at temperatures of 180 and 230°C. By varying the concentration of the ethylene, methyl acrylate and vinyl acetate monomers in the feed, polymers of different composition were obtained. The ratio of the monomer concentrations in the reactor was calculated from the amount of polymer weighed out and its comonomer content as well as the composition of the feed, using the mass balance for the ideal stirred tank reactor. The result was used to determine the reactivity ratios of the three possible binary copolymerisation systems ethylene/methyl acrylate, ethylene/vinyl acetate and methyl acrylate/ vinyl acetate. This made it possible to predetermine, by calculation, the composition of a product obtained by continuous polymerisation in a stirred autoclave.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052110112
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  • 2
    Electronic Resource
    Electronic Resource
    Radical terpolymerization of ethylene, methyl acrylate and vinyl acetate under high pressure. Physical properties of the polymers (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 207 (1993), S. 145-155 
    Details
    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: Um den Einflulß der Reaktionsbedingungen Druck und Temperatur sowie der Comonomeren Acrylsäuremethylester und Vinylacetat auf das entstandene Ethylen-Acrylsäuremethylester-Vinylacetat-Terpolymerisat aufzuzeigen, wurden Polymerisationsversuche in einem kontinuierlich betriebenen Rührautoklaven durchgeführt. Der Druck wurde zwischen 1 100 und 1900 bar variiert. Die Temperatur lag bei 180 bzw. 230°C. Die mittlere Verweilzeit betrug 40 Sekunden. Als Initiator wurden t-Butylperpivalat und t-Butylperethylhexanoat in Konzentrationen von 50 bis 180 mol-ppm im Ethylenzulauf gewählt. Die erhaltenen Polymeren wurden durch Bestimmung ihrer Zusammensetzung, ihrer Dichte, der Kristallinität, des Schmelzpunktes, der Glasßbergangstemperatur, des Schmelzindexes, des mittleren Molekulargewichtes sowie der Zugfestigkeit und Reindehnung charakterisiert.
    Notes: Polymerization tests were carried out in a stirred autoclave designed for continuous operation in order to determine the influence of the reaction pressure and temperature and of the acrylic acid methyl ester and vinyl acetate comonomers on the ethylene-acrylic acid methyl ester-vinyl acetate terpolymer formed. Pressures between 1100 and 1900 bar and temperatures of 180 and 230°C were used. The average residence time was 40 seconds. Tertiary butyl perpivalate and tertiary butyl perethyl hexanoate in concentrations of 50 to 180 mol-ppm in the ethylene feed were used as initiators. The characteristic properties of the polymers obtained were assessed by determining their composition, density, crystallinity, melting point, glass transition temperature, melt index, the average molecular weight, tensile strength and elongation at break.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052070114
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  • 3
    Electronic Resource
    Electronic Resource
    Das Begasen von viskosen Flüssigkeiten durch eine abwärts gerichtete Zweistoff-Düse (2. Teil)Vortrag von W. A. Stein auf der Arbeitssitzung des GVC-Fachausschusses „Technische Reaktionsführung“ am 11./12. Febr. 1982 in Arnoldshain/Taunus. 1. Teil siehe: Chem.-Ing.-Tech. 54 (1982) Nr. 6, S. 616/617, MS 1009/82. (1982)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 54 (1982), S. 928-929 
    Details
    ISSN: 0009-286X
    Keywords: Fermenter ; viskose Flüssigkeiten ; Begaser ; Biotechnologie ; Stoffübergang ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330541017
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  • 4
    Electronic Resource
    Electronic Resource
    Birefringence studies of the stress-induced crystallization of rubbersDedicated to Prof. H. Mark on the occasion of his 80th birthday (1975)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 1 (1975), S. 579-597 
    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 Änderung der Kristallinität als Funktion der Zeit und des Verstreckungsgrades von synthetischem cis-1,4-Polyisopren wird durch gleichzeitige Messung der Doppelbrechung und der Zugspannung untersucht. Die Ergebnisse werden mit Werten verglichen, die aus der durch die Kristallisation bedingten Abnahme der Zugspannung abgeschätzt wurden. Verschiedene Methoden zur Berechnung der Kristallinität aus den experimentellen Daten werden verglichen. Es kann gezeigt werden, daß diese Methode ein empfindliches, einfach zu handhabendes Verfahren zur Bestimmung der Kristallinität dieser Proben darstellt.
    Notes: The change in the fraction crystallinity with time and elongation of synthetic cis-1,4-polyisoprene is studied through simultaneous measurement of birefringence and stress. Results are compared with values estimated from the decrease in stress arising from the crystallization. Various methods for calculating the crystallinity from the data are compared. This method proves to be a sensitive, convenient method for determination of crystallinity of such samples.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1975.020011975138
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  • 5
    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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  • 6
    Electronic Resource
    Electronic Resource
    Über die bestimmung der zahl polymerisationsaktiver zentren von ziegler-natta-katalysatorenHerrn Prof. Dr. Dres. h.c. G. V. Schulz zum 75. Geburtstag gewidmet. Eine modifizierte methode mit 14C-markierten kohlenstoffoxidenVorgetragen auf dem IUPAC “International Symposium on Macromolecules” in Florenz, 7.-12.9. 1980. (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 489-504 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A modified method for the determination of the number of isotactic sites C* and the overall propagation rate constant k̄p of propene polymerization catalysts with 14C-labelled carbon oxides is proposed: an excess of 14CO2 or 14CO is added in the abscence of propene and alkylaluminium to a non-deactivated polymer sample drawn from the polymerization slurry.The specific radioactivity of the polymer as a function of the time of contact with the radio-actively labelled inhibitor sharply increases within short times of contact (14CO2 ≤ 20 min, 14CO ≤ 5 min). This is followed by a slower further increase reaching a finite value after 5 to 7h. The initial and end values differ by a factor of 2 to 3. The results are explained in terms of sites with different reactivity assuming that the total number of isotactic sites is determined only after long times of contact with the inhibitor.So far c* was determined with 14CO2 or 14CO by adding the inhibitor during the polymerization in the presence of propene and alkylaluminium; c* was calculated after short times of contact with the inhibitor, whereas the further steady increase in specific radioactivity was exclusively attributed to side reactions caused by reaction with propene and alkylaluminium.By this modified method we obtained for TiCl3·(1/3)AlCl3 at 60°C k̄p = 13 dm3/(mol·s) and c* = 0,012 mol Ti*/mol Titotal. Addition of a free Lewis base to the polymerization mixture increases c* leaving k̄p unchanged. In contrast to this, if TiCl3·(1/3) AlCl3 is milled with a Lewis base k̄p can be increased by a factor of ≈ 2,5 with lower or equal c* -values. The higher activity of extracted TiCl3-catalyst is due to higher k̄p and c* -values as compared to those using TiCl3·(1/3) AlCl3.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021830218
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  • 7
    Electronic Resource
    Electronic Resource
    Kinetische untersuchungen zur reaktionsfähighkeit von chlormethylgruppen in methylendiphenolen (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 263-279 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The chloromethyl derivatives of 16 differently substituted methylenediphenols were synthesized for the first time. To compare their reactivity, the solvolysis in methanol and the animolysis with an excess of p-nitroaniline in dimethyl sulfoxide were studied kinetically at 25°C. The rate constants for the methanolysis do not differ very much, beside of the fact that para-chloromethyl derivatives react about 100 times faster than ortho-chloromethyl derivatives. However, for the aminolysis a large acceleration up to 103 was found for compounds having both hydroxyl groups in ortho-position to the methylene bridge. Obviously, the cleavage of the O—H bond, which occurs in the rate determining step of the aminolysis, is strongly favoured by an intramolecular hydrogen bond between the phenolic hydroxyl groups.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850205
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  • 8
    Electronic Resource
    Electronic Resource
    Photoreactive cellulose derivatives with comb-like structure, 1. Modification of O-trialkylsilylcellulose with cinnamic acid-containing side chains (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2985-2991 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Trimethyl- and tert-butyldimethylsilylcellulose were esterified with cinnamic acid, 4-nitrocinnamic acid, 4-(hexyloxy)cinnamic acid, 4-(hexadecyloxy)cinnamic acid and N-cinnamoyl-11-aminoundecanoic acid yielding photosensitive comb-like cellulose derivatives. The UV-irradiation of solid films of tert-butyldimethylsilylcellulose cinnamate, trimethylsilylcellulose 4-nitrocinnamate and tert-butyldimethylsilylcellulose-4-hexyloxycinnamate were performed and the decrease of the absorption maxima was correlated with E/Z isomerisation and [2 + 2]-cycloaddition. A possible application of the described photoreactive cellulose esters in the area of membrane technology is discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021911215
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  • 9
    Electronic Resource
    Electronic Resource
    Synthesis and properties of monodisperse polydimethylsiloxane networks (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 2697-2710 
    Details
    ISSN: 0887-624X
    Keywords: monodisperese ; hydrosilylation ; network structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α,ω-Divinyl-terminated polydimethylsiloxane polymers with low polydispersivity were synthesized via anionic polymerization of hexamethylcyclotrisiloxane (D3). Five “monodisperse” polymers with different molecular weights were hydrosilylated with tetrakisdimethylsiloxysilane in the presence of platinum catalysts and inhibitors to form crosslinked networks. Control studies to determine the effect of platinum, silicon hydride, and heat were performed to verify that no redistribution occurred during hydrosilylation. The properties of these cured samples were characterized chemically by degradation with trifluoromethanesulfonic acid in the presence of hexamethyldisiloxane, infrared spectroscopy, and nuclear magnetic spectroscopy. Mechanical properties were studied by measurements of Shore A hardness, dynamic shear modulus, and tensile modulus. The relationship between the molecular weight of the vinyl polymer and the final properties of the cured networks was measured. © 1993 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080311105
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  • 10
    Electronic Resource
    Electronic Resource
    Mixed semiconductor component quantum supralattices: Silver, sodium chloro, iodo-sodalitesThe financial support of the Natural Sciences and Engineering Research Council of Canada (G. A. O., P. M. M., A. S., M. M.), the Ontario Centre for Materials Research (P. M. M.) and the Office of Naval Research (G.D.S.), and technical assistance with the Rietveld refinement from Bill Harrison and Saim Özkar are gratefully acknowledged. (1991)
    Weinheim : Wiley-Blackwell
    Advanced Materials 3 (1991), S. 306-309 
    Details
    ISSN: 0935-9648
    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
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19910030608
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