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  • Polymer and Materials Science  (30)
  • Humans
  • 1970-1974  (19)
  • 1965-1969  (11)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 1681-1700 
    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: Endgroups of unsaturated polyesters formulated with mole ratios of 2/1/3 and 1/1/2 isophthalic acid/maleic anhydride/propylene glycol were modified. Carboxylic acid content was effectively reduced by esterification with alcohols or epoxides, amidation with phenyl isocyanate, or neutralization with amines. Hydroxyl content was reduced by esterification with acids or anhydrides and urethane formation with phenyl isocyanate. Chemical resistance was determined by measuring the decrease in flexural strength and modulus with exposure to 10% solutions of sodium hydroxide and sulfuric acid at 82°C. A 2-week test using the medium chemical-resistant 2/1/3 polyester indicated that any modification which decreased the carboxylic acid content improved chemical resistance. Modifications which increased or decreased the hydroxyl content had no significant effect in the 2-week tests; however, decrease of hydroxyl content appeared important in 6-month exposure tests. The 1/1/2 resins which have high initial chemical resistance had poorer chemical resistance after endgroup modification than the unmodified 1/1/2 resin, with the exception of the phenyl isocyanate-modified product which was equal to the unmodified resin. Water (0.8%) and xylene (0.1%) had no effect on chemical resistance. However, larger amounts of residual solvent were disadvantageous.
    Additional Material: 7 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 943-946 
    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
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 12 (1973), S. 405-421 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The binding of Mg2+ and Mn2+ by DNA by a divalent cation specific electrode and by ultracentrifugation. Both techniques give similar results for the stoichiometry of the reaction. An oscillating densiemete allowed us to detect small changes of volume accompanying the binding. The reaction was also followed by circular dichroism measurements. Interpretation of the results is only possible if one assumes an electrostate site-binding of Mg2+ to phosphate group, and a chelation Mn2+ between the phosphate group and the N7 of the guanine. Physical modifications accompanying these two types of binding are discused and compared to the role of these cations in some biological systems involving DNA.
    Additional Material: 10 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 32 (1973), S. 145-151 
    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: The equilibrium degree of swelling of polystyrene gels prepared by different methods of crosslinking has been measured and compared.Network (1) was prepared by crosslinking a solved polystyrene with bis-chloromethylderivatives of diphenyl by a FRIEDEL CRAFTS reaction, network (2) was prepared by the same method of maximum swollen polystyrene gels precrosslinked by a small amount of divinylbenzene, and network (3) was prepared by crosslinking copolymerization of styrene with divinylbenzene.Though the total degree of crosslinking was identical, the ability of swelling was strongly different: (1) 〉 (2) 〉 (3). Furthermore, the degree of swelling is the higher the smaller the concentration of polystyrene is during the crosslinking reaction.The differences found are explained by the formation of ringentanglements, whose frequency increases with increasing concentration of polystyrene.
    Notes: Der Gleichgewichtsquellungsgrad von Polystyrolgelen, die durch verschieden artige Vernetzungsmethoden hergestellt waren, wurde gemessen und verglichen.Netzwerk (1) wurde durch Vernetzung von gelöstem Polystyrol mit Bis-chlormethylderivaten des Diphenyls durch FRIEDEL-CRAFTS-Reaktion, Netzwerk (2) wurde durch die gleiche Vernetzungsreaktion von bereits durch wenig Divinylbenzol vorvernetzten, maximal gequollenen Polystyrolgelen und Netzwerk (3) durch vernetzende Copolymerisation von Styrol mit Divinylbenzol hergestellt.Trotz gleichem Gesamtvernetzungsgrad ist das Quellvermögen der vernetzten Polystyrole stark verschieden: (1) 〉 (2) 〉 (3). Außerdem ist der Quellungsgrad um so höher, je geringer die Polystyrolkonzentration bei der Vernetzungsreaktion ist.Die gefundenen Unterschiede werden durch Bildung von Ringverschlingungen erklärt,deren Häufigkeit mit steigender Polymerkonzentration zunimmt.
    Additional Material: 1 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 799-800 
    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
    Additional Material: 1 Tab.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 10 (1966), S. 1809-1812 
    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: Dianhydrides from ethylbenzene, cumene, and branched C5-C6 alkylbenzene-maleic anhydride photoadducts have a surprisingly high solubility in epoxy resins. Dianhydrides from benzene, toluene, and n-C10-C13 alkylbenzene adducts, which are homologs of the above, were not soluble. Epoxies cured with the ethylbenzene and cumene dianhydride adducts had higher heat distortion temperatures and flexural strengths than epoxies cured with two commerical monoanhydrides. High-melting polyimides were also obtained with these two new dianhydrides.
    Additional Material: 1 Tab.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 2047-2056 
    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 dielectric constant (ε′) and loss (ε″) of shellac/melamine resin blends have been determined at temperatures between 20° and 120°C and frequencies between 0.1 and 100 kHz. ε′ decreases with increase in the percentage of melamine resin in the blend. Two relaxations have been observed, of ΔH = 4.99 kcal/mole and 11.1 kcal/mole. The glass transition is observed between 60° and 70°C. The cole-cole parameter increases with temperature and becomes constant above Tg.
    Additional Material: 12 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 3739-3744 
    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 concentration profile of a deterrent (di-n-butyl phthalate) which had been diffused into a nitrocellulose sphere (ball propellant) containing nitroglycerin was studied by means of autoradiography. Results indicate a level concentration part way into the sphere with an abrupt dropoff in concentration. An explanation for this type of concentration profile is offered based on hydrogen bonding of the deterrent carbonyl group with unesterified hydroxyl groups in nitrocellulose.
    Additional Material: 2 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Letters 9 (1971), S. 813-822 
    ISSN: 0449-2986
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 13 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 2179-2200 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: p-Chlorophenyldiazonium hexafluorophosphate is shown to be a convenient and effective catalyst for initiating the polymerization of tetrahydrofuran (TH) and other cyclic ethers. The polymerizations apparently proceed without any significant termination or transfer reactions (i.e., “living” polymers result), and materials of very high molecular weight can be obtained. A mobile monomer-polymer equilibrium for THF was obtained during polymerization and equilibrium conversions were determined at a number of temperatures. The ceiling temperature derived from these data was 84°C., the heat of polymerization was -4.58 kcal./mole and the corresponding entropy change was - 17.7 cal./°C.-mole. Hydrocarbons are suitable inert solvents for these polymerizations, but concentrated solutions must be used at ambient temperatures in order to stay above the required equilibrium monomer conceiitration and also to dissolve the catalyst which is insoluble in hydrocarbons. It was shown that acyclic ethers act as transfer agents in these polymerizations and that transfer with consequent reduction of molecular weight continues even after monomer-polymer equilibrium is reached. Cyclic ethers do not act as transfer agents but only copolymerize. Trimethyl orthoformate was shown to be a particularly effective transfer agent; it resulted in a polymer with methoxy endgroups and produced methyl formate as a by-product. The data obtained are consistent with a mechanism involving initiation by hydrogen abstraction and polymerization via tertiary oxonium ions associated with PF-6 gegenions. This gegenion is thought to be responsible for the “living” nature of the system.
    Additional Material: 5 Ill.
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