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  • 1970-1974  (20)
  • 1965-1969  (10)
  • 1830-1839
  • Polymer and Materials Science  (30)
  • 1
    Electronic Resource
    Electronic Resource
    Model connective tissue systems. A physical study of gelatin gels containing proteoglycans (1971)
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 1351-1364 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The swelling behavior of gelatin gels containing proteoglycans (sulphated proteoglycans from bovine intervertebral discs and a hyaluronate proteoglycan from bovine synovial fluid) when immersed in osmotically active solutions of dextran have been measured. The presence of the proteoglycans markedly affects the internal osmotic contribution to the swelling pressure of the gel. These internal osmotic pressures are considerably in excess of the sum of the osmotic activities of the individual components. This behavior is understood in terms of an entropic interaction between the gelatin and the proteoglycan molecules. By use of the “dilute solution” treatment of Flory, the osmotic pressure excesses are related to the volumes and hence dimensions of the interact acting species. A comparison of these values with those calculated by other means shows good agreement. The osmotic behavior of the complex gels can be understood on a mechanistic basis, if we regard the gelatin and sulphated proteoglycans as spheres and the hyaluronate proteoglycan as a rod.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360100808
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  • 2
    Electronic Resource
    Electronic Resource
    Polymere mit dem Zentralatom eines Makrocyclus in der Hauptkette, 1. Polykondensationsreaktionen mit Phthalocyaninsilicium- und Hemiporphyrazingermanium-Verbindungen (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 715-728 
    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: Dihydroxy(phthalocyanino)silicon (1b) and dihydroxy(hemiporphyrazino)germanium (2b) react with different monovalent alcohols to afford low-molecular bisalkoxy derivatives (4 and 5), and with thiophenol the phenylthio derivatives 11a and 11b, resp. With bivalent alcohols and phenols polymers of the structure 6 and 7 or 8a, b, 9a, b, and 10a, b, resp. are obtained.Dichloro(phthalocyanino)silicon (1a) and dichloro(hemiporphyrazino)germanium (2a) react also with phenol, resp. hydroquinone, to give low-molecular and polymeric phenoxy derivatives. The reaction of 1b and 2b with mono- and dibasic carboxylic acids leads to the corresponding esters.The IR-spectra of the prepared compounds are discussed. Thermogravimetric and semiconductive measurements (σ298K ≈ 10-7 to 10-16Ω-1cm-1) are described.
    Notes: Dihydroxyphthalocyaninsilicium (1b) und Dihydroxyhemiporphyrazingermanium (2b) werden mit verschiedenen einwertigen Alkoholen zu den niedermolekularen Bisalkoxy-Derivaten (4 bzw. 5) und mit Thiophenol zu den Phenylthio-Derivaten (11a und 11b) umgesetzt. Mit zweiwertigen Alkoholen und Phenolen köml;nnen Polymere der Struktur 6 und 7 bzw. 8a, b, 9a, b und 10a, b erhalten werden. Dichlorphthalocyaninsilicium (1a) und Dichlorhemiporphyrazingermanium (2a) reagieren mit Phenol bzw. mit Hydrochinon ebenfalls zu niedermolekularen und polymeren Phenoxy-Derivaten. Die Umsetzung von 1b und 2b mit einund zweibasischen Carbonsäuren führt zu den entsprechenden Estern.Die IR-Spektren der dargestellten Verbindungen werden diskutiert. Thermogravimetrische und Halbleitermessungen (σ298K ≈ 10-7 bis 10-16Ω-1cm-1) werden beschrieben.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750302
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  • 3
    Electronic Resource
    Electronic Resource
    Teilchen-Detektoren. Von 0. C. Allkofer. Thiemig-Taschenbuch Band 41, Verlag Karl Thiemig KG, München, 1971. XVIII; 248 S.; 155 Abb., 5 Tab., kart.-cellophaniert DM 19,80 (1971)
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 22 (1971), S. 987-987 
    Details
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/maco.19710221123
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  • 4
    Electronic Resource
    Electronic Resource
    Eine optische Methode zur kontinuierlichen Verfolgung langsamer KorrosionsvorgängeHerrn Prof. Dr. E. Bartholomé zum 65. Geburtstag gewidmet (1974)
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 25 (1974), S. 235-238 
    Details
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: An optical method for continuously following slow corrosion processesThe method presented here is based on the variation of the optical transmittance and, consequently, can be applied to very thin (some 1000 Å ) metal layers only. Because of the high absorption coefficients of metals it is possible by this method to follow dissolution processes of the order of monoatomic layers. The light source used is a He-Ne-laser. The following applications are described: dissolution rate of chromium in the transpassive range; dissolution of gold in sulfuric acid with additions of hydro chloric acid; photolytic corrosion of titanium.
    Notes: Die hier verwendete Methode beruht auf der Veränderung der optischen Durchlässigkeit und kann infolgedessen nur auf sehr dünne (einige 1000) Metallschichten angewendet werden. Aufgrund der hohen Werte der Absorptionskoeffizinten von Metallen ist es möglich, mit dieser Methode Auflösungsvorgänge in der Größenordnung monomolekularer Schichten zu verfolgen. Als Lichtquelle wird ein He-Ne-Laser verwendet. Beschrieben werden die folgenden Anwendungen: Auflösungsgeschwindigkeit von Chrom im Bereich der Transpassivität;Auflösung von Gold in Schwefelsäure mit HCL Zusatz;photolytische Korrosion von Titan.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/maco.19740250402
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  • 5
    Electronic Resource
    Electronic Resource
    Zur kinetik der niederdruckpolymerisation von äthylen mit löslichen ZIEGLER-katalysatoren (1973)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 169 (1973), S. 163-176 
    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: This paper deals with the kinetics of the low pressure polymerization of ethylene catalysed by the soluble ZIEGLER-catalyst (C5H5)2Ti(C2H5)Cl/Al(C2H5)Cl2. By a special technique it was possible to study for the first time the kinetics of the initial homogeneous part of the polymerization. The following results were obtained: The active species of this catalyst system is formed extremely rapid and seems to be a very dynamic equilibrium product. Its concentration depends on the ratio Al/Ti. The propagation reaction therefore corresponds to an intermitting process. The propagation rate constant was estimated to 15 dm3 · mol-1 · s-1 for 10°C. An excess of the aluminum component (Al/Ti 〉 1) acts as deactivator. The polymerization of the heterogeneous system is probably diffusion controlled. Therefore, the rate decay of the polymerization cannot be described by simple kinetic laws. For small ratios Al/Ti the polymerization has the character of a “living” system.
    Notes: Es wird die Kinetik der Äthylenpolymerisation mit dem löslichen Katalysatorsystem (C5H5)2Ti(C2H5)Cl/Al(C2H5)Cl2 behandelt. Mit Hilfe einer speziellen Meßmethode konnte erstmals der homogene Anfangsbereich der Polymerisation kinetisch erfaßt werden. Anhand der erzielten Befunde lassen sich folgende Schlußfolgerungen ziehen: Die polymerisationsaktive Spezies wird unmeßbar rasch nach dem Mischen der Katalysatorkomponenten gebildet und ist als ein sehr dynamisches Gleichgewichtsprodukt anzusehen, dessen Konzentration vom Verhältnis der Katalysatorkomponenten abhängt. Kettenwachstum ist demnach ein intermittierender Vorgang. Die Geschwindigkeitskonstante der Wachstumsreaktion wurde zu etwa 15 dm3 · mol-1 · s-1 für 10°C bestimmt. Überschüssiges Aluminium-organyl (Al/Ti 〉 1) wirkt desaktivierend. Die Polymerisation in heterogener Phase ist sehr wahrscheinlich diffusionsbestimmt. Die Abnahme der Polymerisationsgeschwindigkeit mit der Zeit ist komplexer Natur und ist mit einfachen kinetischen Zeitgesetzen nicht zu beschreiben. Die zeitliche Zunahme des Polymerisationsgrades für Verhältnisse Al/Ti = 2 weist darauf hin, daß die Polymerisation den Charakter eines „lebenden“ Systems aufweist.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1973.021690116
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  • 6
    Electronic Resource
    Electronic Resource
    Dynamic viscoelastic properties of solutions of shear-degraded deoxyribonucleic acid (1967)
    New York : Wiley-Blackwell
    Biopolymers 5 (1967), S. 123-130 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Calf thymus and salmon sperm deoxyribouncleie acid were degraded by high-shear stirring to molecular weights M in the range of 1.3-3.2 × 106 and purified by chromatography on methylated bovine serum albumin. Dynamic viscoelastic properties of the fragmented products, in aqueous glycerol solutions in the concentration range of c = 0.003-0.01 g./ml., were investigated with the apparatus of Birnboim and Ferry. At values of the product cM higher than 4 × 103, the frequency dependence of the components of the complex shear modulus, G′ and G″, displayed a plateau region in which G′ 〉 G″ - ων1ηS, similar to that observed in concentrated solutions of coiling polymers where it is attributed to an entanglement network (ω is radian frequency, ν1 volume fraction of solvent, and η8, solvent viscosity). The width of this plateau region on the logarithmic frequency scale is given by Δ = 3.8 (log cM - 3.56). At lower values of cM, the frequency dependence is intermediate between those predicted by the theory of Zimm for flexible coiled macromolecules and by the theory of Kirkwood and Auer for rods. Fitting to the Zimm theory gives highly discrepant values for molecular weights, while fitting the low-frequency end of the dispersion to the Kirkwood-Auer theory gives reasonable agreement for both molecular weight and rotary diffusion coefficient. It is concluded that the helical fragments appear as nearly rigid rods in their behavior at very low frequencies, but at higher frequencies reveal substantial bending flexibility.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1967.360050112
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  • 7
    Electronic Resource
    Electronic Resource
    Physical behavior of gelatin gels: A simple model for connective tissue (1971)
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 35-46 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The swelling behavior of gelatin gels when immersed in buffer or in osmotically active solutions of dextran 500 has been studied, and the results can be described by means of the Flory-Rehner theory of the thermodynamic properties of three-dimensional network structures. The density of crosslinkages formed in the gel is found to be related to the concentration of gelatin at which gelation occurs. Values of rigidity moduli are estimated from the density of crosslinkages by use of the statistical thermodynamic theory of rubber elasticity. These values are in excellent agreement with direct measurements.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360100105
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  • 8
    Electronic Resource
    Electronic Resource
    Storage and retrieval of macromolecular structural dataAmer. Crystallograph. Assoc. Winter Meeting, Ser. 2, vol. 1, 1973, paper F-7; and NATO/CNA Advanced Study Inst. on Computer Representation and Manipulation of Chem. Inform., Noordwijkerhout, The Netherlands. (1974)
    New York : Wiley-Blackwell
    Biopolymers 13 (1974), S. 419-422 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1974.360130220
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  • 9
    Electronic Resource
    Electronic Resource
    [η]-M-Beziehung von PolyoctenamerenHerrn Prof. Dr. Heinrich Hellmann zum 60. Geburtstag gewidmet (1974)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 37 (1974), S. 97-103 
    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: Solution properties of polyoctenamers were studied. A relation [η]-M in toluene at 25°C was elucidated. The kθ-value derived from this relation agrees quite well with similar data of polybutadiene, polypentenamer and polyethylene. No evidence was found for the existence of cyclic structures in polyoctenamers.
    Notes: Lösungseigenschaften von Polyoctenameren wurden untersucht. Eine Viskositäts-Molekulargewichts-Beziehung in Toluol bei 25°C wurde ermittelt. Der daraus abgeleitete kθ-Wert stimmt mit den für Polybutadien, und Polyäthylen bekannten Werten überein. Ein Hinweis auf die Existenz von ringförmigen Makromolekülen konnte nicht gefunden werden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1974.050370108
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  • 10
    Electronic Resource
    Electronic Resource
    Über eine anomale Teilchenbildungsphase bei der Emulsionspolymerisation von SBRHerrn Prof. Dr. Heinrich Hellmann zum 60. Geburtstag gewidmet (1974)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 39 (1974), S. 167-174 
    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 the course of emulsion polymerization of SBR the rate of polymerization during the stage of particle formation is running through a significant maximum, if initiation takes place with a redox-system, consisting of the partially oil-, partially water-soluble components pinenehydroperoxide, ethylenediamine-tetraacetic acid, ferrous sulfate and rongolite. This anomaly is discussed by means of a reaction scheme, which, among other steps, postulates radical formation directly in the micelles themselves.
    Notes: Bei der Emulsionspolymerisation von SBR durchläuft die Polymerisationsgeschwindigkeit während der Teilchenbidungsphase ein ausgeprägtes Maximum, wenn als Initiator das aus den teils öl-, teils wasserlöslichen Komponenten Pinanhydroperoxid, Äthylendiamintetraessigsäure, Eisensulfat und Rongalit bestehende Redoxsystem eingesetzt wird. Diese Anomalie wird an Hand eines Reaktionsschemas diskutiert, das u. a. von einer Radikalbildung unmittelbar in den Mizellen ausgeht.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1974.050390114
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