Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1975-1979  (2)
  • 1977  (2)
Source
Material
Years
  • 1975-1979  (2)
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Irradiation of poly(vinyl alcohol) fibers in the presence of chloroform and carbon tetrachloride (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 2913-2920 
    Details
    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: Radiolysis of poly(vinyl alcohol) fibers (PVA) in the presence of chloroform and carbon tetrachloride was investigated. Decrease in intrinsic viscosity was observed at lower dosages (up to 2.3 megarads); and above this, an increase was noted. The blank samples irradiated under similar conditions showed a continuous decrease in intrinsic viscosity. A discoloration in the samples irradiated in the presence of CCl4 and CHCl3 was also observed. It is attributed to double bond formation in the backbone. A marginal decrease in the tensile strength of the irradiated fibers was observed. However, the surface characteristics of the fibers did not change on irradiation. The thermogravimetric analysis revealed a better heat resistance in irradiated fibers.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070211107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stability of polyamic acids and polyimides (1977)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 64 (1977), S. 101-113 
    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: Polyamidsäuren wurden aus Pyromellithsäuredianhydrid und Benzidin (B) sowie Hydrazin (H) dargestellt und druch Viskositätsmessungen in Dimethylformamid (DMF) charakterisiert. Die Hydrolysestabilitßat wurde nach 20tägige Aufewahrung der DMF-Lösungen an der Luft bei Raumtemperatur ermittelt. Es ergab sich eine Viskositätsabnahme für die B-Polymeren und die Copolymeren mit B und H. Diese Verminderung ist für die Copolymeren geringer.Das thermische Verhalten der Polyamidsäuren und Polyimide wurde mittels thermogravimetrischer und differentialthermoanalytischer Methoden untersucht. Die Copolyamidsäuren wiesen eine größere thermische Stabilität als die Polyamidsären aus B auf, während die Copolyimide eine geringere Stabilität als die Polyimide aus B aufwiesen. Die thermische Cyclodehydrierung der Polyamidsäuren zu den polyimiden fand bei den Copolymeren bei geringeren Temperaturen als bei den B-Polymeren statt.
    Notes: The polyamic acids from pyromellitic dianhydride, benzidine (B) and hydrazine (H) were prepared and characterized by intrinsic viscosity measurements in dimethylformamide (DMF) solutions. The hydrolytic stability of these polymers was determined by keeping the DMF solution in presence of air at room temperature for 20 days. A decrease in ηinh was observed for the B-polymers and copolymers of B and H. This reduction was less in the copolymers.The thermal behaviour of polyamic acids and polyimides was studied by thermogravimetric and differential thermal analysis techniques. The copolyamic acids were found to be thermally more stable than polyamic acid from B at higher weight losses (about 50%), whereas copolyimides were found to be less stable than polyimide from B. Thermal cyclodehydration of polyamic acids to polyimide occurred at lower temperatures in copolymers than the polymer of B.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1977.050640109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...