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  • 1965-1969  (14)
  • Polymer and Materials Science  (14)
  • Inorganic Chemistry
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 2811-2817 
    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: When hexaphenylcyclotrisilazane was heated above 450°C. at atmospheric pressure, it formed an infusible polymer of exceptional thermal and chemical stability. The polymerization, which was accompanied by elimination of benzene, is represented approximately by the equation: \documentclass{article}\pagestyle{empty}\begin{document}$\eta [({\rm C}_6 {\rm H}_5)_2 {\rm SiNH}]_3\,\, \to \,\,({\rm C}_6 {\rm H}_5 {\rm SiN})_{3n} + 3n{\rm C}_6 {\rm H}_6$\end{document} The infusible polymer was a foamed, vitreous, pale yellow solid with a high degree of stability to heat, acids, alkali, and organic solvents. A similar reaction occured with a resein that was obtained as a by-product in the preparation of hexaphenylcyclotrisilazane and with a mixture of silylamines that was obtained from the reaction of methylphenyldichlorosilane with ammonia. Coatings on aluminum and steel prepared by heating the silylamine polymers had good thermal stability and adhesion. Inclusion of a polymeric dimethylsilyl derivative of ethylenediamine improved the flexibility of the coatings.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 12 (1968), S. 23-34 
    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: Several series of ABA-type “tapered” block polymers of styrene (monomer A) with isoprene or butadiene were prepared with the use of n-butyllithium or sec-butyllithium as initiators in benzene solution. The stress-strain curves of the raw polymers are reported, showing that many of them behave at ambient temperature like vulcanized elastomers. These polymers consist, however, of completely linear chains, with no chemical crosslinks between them; they are thermoplastic, can be easily molded, and are soluble in common solvents. Hence, they may be classed as pseudo-crosslinked elastomers. Better stress-strain properties are obtained from polymers made with sec-butyllithium than with n-butyllithium; in turn, polymers from butadiene have better properties than those from isoprene. Stress-strain curves most closely resembling those of crosslinked elastomers are obtained in general from polymers containing about 30-45% styrene. It was found that AB-type block polymers have very poor tensile strengths and low elongations. The microstructures of polybutadienes and polyisoprenes of various molecular weights, prepared in benzene solvent with alkyllithium initiators, were also determined and compared with literature data for like polymers prepared in cyclohexane solvent.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 3
    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: The role of certain inorganic salts in increasing the flux of water through semipermeable membranes of cellulose acetate is related to the capacity of the component ions to swell the cellulosic substrate. The mechanism whereby ions which are high on the Hofmeister lyotropic series swell and dissolve secondary cellulose acetate has been investigated. Swelling is effected by the formation of metastable complexes involving the highly hydrated cationic fraction of the salt and both the hydroxyl and acetate groups of the cellulose acetate. Whereas effective anions possess large ionic radii and cause a breakdown in the structure of water which results in increased hydration of the cation, ineffective anions possess higher charge densities and tend to pair with the cation and decrease the latter's electrophilicity and hence hydratability. Ionic charge density is the factor of prime importance both with respect to the hydratability of the cation and the tendencies toward water disaggregation and ion association of the anion. The mechanism involved in the swelling of secondary cellulose acetate is related to swelling phenomena in many other polymers containing polar groups.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 4
    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 quantitative study has been made of the effects on the membrane gel structure of parameters whose significance with respect to desalination performance had previously been empirically established. The composition of the polymer solutions, the fabrication temperatures, and the pressure employed during desalination are shown to be related, in that they all influence the swelling behavior of the gel structure. The relationship which has been found between the water content and the rate of water transport across semipermeable membranes of cellulose acetate is explained on the basis of a solution transport mechanism.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 5
    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: The mechanism by which water and dissolved salts permeate selectively through membranes has been investigated. It has been demonstrated that the predominant mechanism of permeation involves the interaction of the various species with specific sites and their associated bound water molecules. The extent of the bound water held by the cellulosic membranes of interest has been determined. Correlation has been found between the permeation characteristics demonstrated by membranes at various steps in their preparation and its bound water content. The mechanism of rejection of salts has been shown to be related to the relative inability of their ions to become solvated by bound water. A model has been hypothesized which correctly describes the behavior of the desalination membrane with reference to water and soluble inorganic salts.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 3 (1969), S. 191-206 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The nature of the events occurring immediately after exposing foreign surfaces to fresh flowing blood was assessed using a combination of MAIR infrared spectroscopy, ellipsometry, and contact angle measurements. Within the first 5 sec after contact with blood issuing from the jugular veins of lightly anesthesized dogs, germanium prisms were uniformly coated with strongly adherent proteinaceous filsm having an average optical thickness equivalent to 2 layers of stearic acid (approx. 50 Å) and having critical surface tensions of about 36 dyne/cm. A contact time of 60 sec led to a less uniform coating of average optical thickness equivalent to 5 layers of stearic acid (approx. 125 A), but with similar MAIR spectrum and wettability. The internal refelection spectra were consistent with the presence of either alpha-helical or random-chain configurations, but not with the extended chain beta-structure for proteins. Films cast from purified fibrinogen on platinum foils gave similar spectra and exhibited similar wetting properties; these observations are consistent with the hypotehsis that initial adsorptive events are dominated by fibrinogen deposition. The involvement of small amounts of lipid or other protein remains a distinct possibility, however.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Letters 3 (1965), S. 1049-1052 
    ISSN: 0449-2986
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 251-256 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Terpolymerizations of ethylene, propylene, and dicyclopentadiene were carried out in which the dicyclopentadiene was added to the reaction system in two equal portions at the beginning and midpoint of each run, while the monoolefins were added continuously. In the resultant elastomers, unsaturation remains much more constant throughout the course of the polymerization than for terpolymers obtained when all dicyclopentadiene is added at the start of the reaction. Yield and molecular weight of the terpolymers produced by either technique are quite comparable, however. With VCl4 catalyst (with Al2Et3Cl3 cocatalyst) in heptane solvent, the two-step addition of the diene gave terpolymers with little gel, in contrast to the high gel in terpolymers formed with the single initial addition of the diene. This system also produced terpolymer with the highest final unsaturation and molecular weight. Catalysts of VCl4, VOCl3, or V(C5H7O2)3 in benzene gave terpolymers of moderate unsaturations and molecular weights.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 1203-1208 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vanadium trisacetylacetonate [V(C5H7O2)3] and vanadyl bisacetylacetonate [VO-(C5H7O2)2] were found to be satisfactory catalysts (with Al2Et3Cl3 cocatalyst) for the terpolymerization of ethylene, propylene, and dicyclopentadiene to unsaturated, sulfurcurable elastomers. Polymerization solvents of heptane or benzene were used. Best yields of terpolymers were obtained in benzene. Terpolymers with unsaturations of greater than ≃0.20 mole C=C/kg. can be cured with a sulfur-based vulcanzing recipe. Both acetylacetonates produced terpolymers, in benzene, with practically equivalent properties. They also appeared to be nearly equal to corresponding terpolymers made with catalysts of VOCl3 or VCl4.
    Additional Material: 2 Tab.
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 3157-3164 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ethylene, propylene, and dicyclopentadiene were terpolymerized to form unsaturated, sulfur-curable elastomers, by use of catalysts of VCl4 or VOCl3 (with Al2Et3Cl3 cocatalyst) and polymerization solvents of heptane, benzene, or tetrachloroethylene. Of the various possible catalyst-solvent combinations, best overall balance of results was given by VOCl3 catalyst in benzene solvent. All other combinations, except one, also gave good results, however, with some having special points of merit. The exception was VOCl3 in heptane solvent, which produced erratic yields of highly gelled polymer. A limited study was made of the effect of the dicyclopentadiene concentration on polymerization. Increasing the diene concentration decreased polymer yield but increased its unsaturation; it had no gross effect on the inherent viscosities of the polymers. Terpolymers containing more than about 0.30 mole C=C/kg. can be cured tightly with sulfur-based vulcanizing recipe.
    Additional Material: 1 Tab.
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