Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (6)
  • 1960-1964  (6)
Collection
Keywords
Publisher
Years
Year
  • 1
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Previous nuclear magnetic resonance measurements on a polymethylsiloxane gum (MW = 75,000) had been interpreted to indicate the presence of considerable segmental motion in both the amorphous and crystalline components at temperatures above the glass temperature. Further investigation again showed the NMR line to be completely narrowed just above the glass point indicating such motions must extend into the crystalline component. This work was extended by the measurement of NMR absorption line widths for temperatures of 80-300°K. on samples of the same gum subjected to gradually-increased crosslinking by electron doses of 3-600 × 106 rep. Here, no change in the NMR properties of low temperature, rigid states were observed, but the room temperature line width progressively increased from 0.019 gauss to over 0.100 gauss peak-to-peak due to the increase in bulk viscosity of the liquid. The “first-order” activation energy associated with the temperature-dependent line narrowing decreased from 10 to 2 kcal./mole. The NMR data indicate that the primary effects of radiation-induced crosslinking are to reduce the chain rotational energy by the creation of defects and to increase the short-range viscosity by the lowering of translational freedom.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    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: Crystals of amylose were prepared by precipitation from aqueous solution with n-butanol. The crystals are rectangular platelets, and crosses or rosettes formed by the intergrowth of single platelets. In the electron microscope they are seen to consist of layers 75 A. in thickness. Distinct spiral terrace growths related to screw dislocations were not observed, but the presence of dislocation edges suggests that the crystals thicken by a dislocation mechanism. Low-angle, x-ray measurements on aggregates of the crystals reveal a long spacing in good agreement with that calculated from shadow lengths. However, in contrast with other polymers, the long spacing appears to be invariant with crystallization temperature. Electron diffraction spot patterns show that the platelets are single crystals and indicate that the chain molecules are folded within the lamellae.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 47 (1960), S. 509-512 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    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: Sodium chloride and sodium hydroxide raise considerably the water vapor sorption of casein, hydrochloric acid, however, decreases it to a very small extent. Casein binds sodium and chloride ions in equilibrium with saturated sodium chloride solution, and the number of bound ions corresponds roughly with the maximum acid binding capacity of this protein.
    Notes: Natriumchlorid und Natriumhydroxyd erhöhen die Wasserdampfsorption von Casein beträchtlich, Salzsäure erniedrigt sie sehr wenig. Im Gleichgewicht mit gesättigter Kochsalzlösung werden von Casein Natrium- und Chlorionen in einer Zahl gebunden, die der maximalen Säurebindungsfähigkeit größenordnungsmäßig entspricht.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    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: Single crystals of cellulose triacetate were prepared by supercooling dilute solutions in mixtures of nitromethane and n-butanol. The crystals are approximately square in shape and thicken by spiral growths centered on screw dislocations. The chain molecules are perpendicular to the lamellae which are about 180 A. thick. In spite of their stiffness the molecules appear to assume folded configurations in the lamellae. Various morphological features of the crystals are described and discussed.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    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: Crystals of cellulose triacetate were hydrolyzed in an attempt to obtain single crystals of cellulose. The hydrolyzed material retains the morphology of the triacetate crystals, but its crystalline state depends upon the method of hydrolysis. In an aqueous medium, polycrystalline cellulose is formed, while a nonaqueous medium gives an amorphous cellulose. The results suggest that the hydrolysis is accompanied by a disruption of the lattice and that recrystallization of the resulting amorphous cellulose is caused by the water.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...