WILBERT

Wildauer Bücher+E-Medien Recherche-Tool

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0933-5137
    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
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Advanced Materials 5 (1993), S. 854-856 
    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: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The role of chain entanglements in determining the stress-strain properties of polybutadiene networks has been investigated. The number of entanglements was varied by changing the primary molecular weight and chemical crosslink concentration. Networks essentially free of entanglements were prepared by endgroup coupling of carboxy terminated polybutadiene of 5500 molecular weight. Conventional sulfur or peroxide vulcanizates obeyed the Mooney-Rivlin stress-strain relation, the constant C2 which represents the deviation from simple kinetic theory diminishing with the time allowed for approaching elastic equilibrium. The constant C2 was found to increase with both the total physical crosslinking and the entanglement contribution to this quantity. The endgroup vulcanizates obeyed the simple kinetic theory of rubber elasticity and approached elastic equilibrium much more rapidly than sulfur or peroxide vulcanizates. The evidence presented suggests that the apparent deviation of elastomeric vulcanizates from the kinetic theory of rubber elasticity resulting in the appearance of the Mooney-Rivlin C2 term in the stress-strain relation arises from a slow relaxation process involving the entanglement crosslinks.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 1101-1109 
    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: Glass beads were encapsulated by grafted polymers: polybutylacrylate and polystyrene. Grafting was performed by the polymerization initiated from the particle surface with preliminary adsorbed polyperoxide initiator. Grafting procedure and properties of grafted film were studied using model substrates: powders, plates, and wafers by wetting technique and SEM. Conditions of grafting affect the film structure. They are porous, and due to some sort of pores the wetting liquid is able to penetrate into covering and reach the substrate. Model epoxy composites were prepared with covered glass beads. The coverings allowed a decrease of adhesion between the matrix and bead surface to detect acoustic emission caused by the debonding process. The dependence of debonding stress from covering the structure and nature was studied. © 1996 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 60 (1977), S. 215-248 
    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: Die Verstärkung von Elastomeren durch Ruß wird durch die Morphologie des Rußes und seine physikalischen und chemischen Wechselwirkungen mit dem Polymeren geprägt. Letztere werden stark durch Graphitierung und Oberflächenoxidation beeinflußt. In modernen Gummi-Rußen werden feste Bindungen zwischen Polymeren und der Kohlenoberfläche nach verschiedenen Mechanismen gebildet; da die Oberflächen der Ruße chemisch nur wenig unterschiedlich sind, wird die Morphologie zum dominierenden Charakteristikum. Sie wird bestimmt durch die mittlere Größe und die Größenverteilung der Teilchen, die sich zu Primäraggregaten, ähnlich verzweigten statistischen Knäueln, zusammengelagert haben, durch die räumliche Anordnung der Teilchen in diesen Aggregaten, sowie die Zahl der Partikel pro Aggregat und ihre Verteilung. Diese sehr komplexe Morphologie kann in erster Näherung durch die dem Kautschuk zugängliche spezifische Oberfläche und durch irgendein Maß für das von den Primäraggregaten durchdrungene Volumen („Struktur“) dargestellt werden. Wichtige mechanische Eigenschaften hängen in unterschiedlichem Ausmaß von diesen beiden Charakteristiken, oft in sehr komplexer Weise ab. Der Einfluß auf die viskoelastischen und die Bruch-Eigenschaften wird diskutiert. Zusätzlich werden einige neue Beobachtungen über den Einfluß von Ruß auf die Netzwerkstruktur und den Einfluß der Verteilungsbreite der Aggregatgröße auf das viskoelastische Verhalten erläutert.
    Notes: The reinforcement of elastomers by carbon black is governed by the morphology of the black and its physical and chemical interactions with the polymer. The latter are strongly affected by graphitization and surface oxidation. In modern rubber-grade carbon blacks strong bonding of the polymer to the carbon black surface is effected by several mechanisms, but surface chemical differences between blacks are relatively small, so that the dominant characteristic becomes the morphology. This is determined by the average size and size distribution of the particles which are fused together to form primary aggregates resembling branched random coils, the spatial arrangement of the particles in these aggregates, and the number of particles per aggregate and its distribution. This highly complex morphology can, to a first approximation, be represented by the specific surface area accessible to rubber and some, usually indirect, measure of the volume pervaded by the primary aggregates (“structure”). Important mechanical properties of reinforced rubbers depend to different degrees on these two characteristics, often in rather complex manner. Their effects on viscoelastic and failure properties are described. Additionally, some very recent observations on the effects of carbon black on network structure and the influence of the breadth of the aggregate size distribution on viscoelastic behavior are discussed.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 192 (1991), S. 93-101 
    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: Die Sauerstoffpermeabilität von Halbestern und Halbamiden der Styrol-Maleinsäure-Copolymeren und weiterer carboxygruppenhaltiger Polymerer wurde im Vergleich mit kommerziellen glasbildenden Polymeren bei Raumtemperatur untersucht. Die Löschung der verzögerten Fluoreszenz von Pyronin B diente zum Nachweis des Sauerstoffs im Polymerfilm.Die Sauerstoffpermeabilität des Styrol-Maleinsäureanhydrid-Copolymeren und der Halbester und Halbamide (Pox = 2…7°10-14 cm2/Pa·s) ist vergleichbar mit der von Polymeren ohne Carboxygruppen wie Polymethylmethacrylat (PMMA) oder Polyvinylacetat (PVAc) und liegt damit etwa eine Größenordnung über der von Polyacrylsäure (PAAc), Styrol-Maleinsäure-Copolymeren (SMAc) oder Carboxymethylcellulose (CMC). Vermutlich konkurrieren intramolekulare H-Brücken in den Halbestern/Halbamiden erfolgreich mit der intermolekularen Wechselwirkung und bewirken damit ebenso wie raumfüllende Substituenten eine Erhöhung der Permeabilität. Zusatz von Basen wie Dimethylaminopropanol (DMAP) und Dimethylaminopropylacrylamid (DMAPAA) senkt die Permeabilität auf bis zu 1/40 des Ausgangswertes ab, was der niedrigen Permeabilität von Polymeren mit vorherrschender ionischer Wechselwirkung (Na-Polyacrylat (NaPAAc), Na-Carboxymethylcellulose (NaCMC) nahekommt.
    Notes: The paper gives a report on the oxygen permeability in films of poly(styrene-comaleic acid) halfesters and halfamides as well as other polymers containing carboxylic groups in comparison with commercially available glass forming polymers at room temperature. The presence of oxygen in the polymer layers was proved by the quenching of the delayed fluorescence of pyronin B. The permeability of the halfesters/halfamides (Pox = 2…7.10-14 cm2/Pa .s) corresponds to that of common polymers like poly(methyl methacrylate) (PMMA) or poly(vinyl acetate) (PVAc), and is nearly one order of magnitude higher than that of poly(acrylic acid) (PAAc), poly(styrene-comaleic acid) (SMAc) and carboxymethylcellulose (CMC). Presumably, intramolecular hydrogen bonds in the halfester/halfamides compete successfully with the intermolecular interactions and hence cause an increase in permeability as also do bulky substituents. Addition of bases like dimethyl aminopropanol (DMAP) and dimethyl aminopropyl acrylamide (DMAPAA) decreases the permeability to about 1/40 of the initial value. The permeability is then similar to the low permeability of polymers with predominant ionic interaction sodium polyacrylate (NaPAAC), sodium carboxymethylcellulose (NaCMC)).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 861-871 
    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 theory is developed to account for the restricted swelling in solvents of crosslinked elastomers containing reinforcing fillers. Assuming swelling to be completely restricted at the filler-rubber interface due to adhesion, the following relation is obtained: \documentclass{article}\pagestyle{empty}\begin{document}$$ v_{ro} {\rm /}v_r {\rm } = {\rm 1} - [3c(1 - v_{ro} {}^{1/3}){\rm } + {\rm }v_{ro} - 1]\phi /(1 - \phi ), $$\end{document} where vr is the volume fraction of rubber in the swollen rubber phase, Vro is the same quantity referred to on otherwise analogous, unfilled vulcanizate, Φ is the volume fraction of filler, and c a parameter depending on the filler, but independent of Φ and Vro. This equation is shown to hold for a large volume of experimental data on carbon blacks, involving four rubbers, several sulfur vulcanizing systems, five solvents, and a wide range of crosslinking. Conformance with the theory indicates that carbon blacks are firmly bonded to the rubber and that, in the sulfur crosslinking systems investigated, they have no significant effect on the stoichiometry of vulcanization (although they may affect the rate of vulcanization). Illustrative examples of applications of the theory to problems in filler reinforcement and vulcanization are shown.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 1257-1263 
    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: Using a relationship found to be applicable for natural rubber networks in establishing contributions of chemical crosslinking, entanglements, and networks defects to physical crosslinking, a physical versus chemical crosslinking “calibration” is developed for polybutadiene prepared by organolithium initiation. This calibration is then used to determine chemical crosslink yields for sulfur-sulfenamide, thiuram, and peroxide vulcanization. Crosslink yields for polybutadiene in the sulfur-sulfenamide and thiuram curing systems are shown to be similar to those of natural rubber. In peroxide vulcanization the crosslink yield is in excess of unity for polybutadiene. Evidence is presented which indicates that this is due to a polymerization type reaction involving vinyl groups resulting from 1,2-addition during polymerization.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 8 (1964), S. 2585-2604 
    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: Cold mastication of natural rubber in presence of oxygen leads to scission by a shear mechanism with subsequent stabilization of the free radicals by oxygen, while at high temperatures oxidative scission becomes the dominant mechanism. Studies of the behavior of cis-polybutadiene reveal that similar reactions are effective, but occur at much reduced rates. Shear degradation is particularly difficult to achieve in typical cis-polybutadienes. This is related to the molecular weight distribution of these polymers which usually lack the very high molecular species most subject to shear-induced degradation, in agreement with the theory of F. Bueche. It is shown that when such a high molecular weight fraction is supplied, shear breakdown may be realized. All cis-polybutadienes undergo oxidative breakdown at high temperatures, the scission rate becoming appreciable above 140°C. A number of oxidation catalysts have been found which markedly increase the scission rate without leading to a correspondingly large increase in crosslinking. Significant improvements in processing may be realized in this manner.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 445-452 
    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: Salts contained in aromatic polyamide solutions were found to have a considerable effect on the performance and structure of reverse osmosis membrannes cast from these solutions. As in cellulose acetate membranes, certain salts greatly increase membrane fluxes without a detrimental effect on rejection. Highly dissociated salts such as LiClO4 or Mg(ClO4)2 exert a stronger influence than the commonly used LiCl. With mixtures of different salts, stronger effects may be obtained than with a single additive. Many experimental facts indicate that the “salt effect” in aromatic polyamide membranes is due to a general effect on solvent activity and thus on the kinetics and equilibria associated with evaporation and coagulation process.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...