Library

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
  • fluorescence polarization  (3)
  • Polyvinylchloride  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 260 (1982), S. 1017-1022 
    ISSN: 1435-1536
    Keywords: Cold drawing ; free volume ; annealing ; Polyvinylchloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cold drawing of PVC-films at room temperature depends on thermal pretreatment. Yield stress, difference between yield and draw stress and neck temperature increase, when the samples have been annealed not far below glass transition temperature and subsequently quenched; they decrease by annealing aboveT g and quenching down to room temperature. These changes of variables characterizing the cold drawing process can be interpreted morphologically by an increase or decrease of free volume in the noncrystalline regions which favour neck formation or render it more difficult respectively.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1435-1536
    Keywords: Noncrystalline polymers ; Hermans' orientation factor ; dichroism ; fluorescence polarization ; birefringence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract PVC- and PC-films doped with various fluorescent molecules were uniaxially drawn below and just above the glass transition temperature. The orientation of fluorescent probes and polymer segments is discussed, comparing Hermans' orientation factors evaluated from birefringence for the segments and from dichroism and fluorescence polarization for the probes. Moreover, the orientation of the fluorescent probes is related to that of hypothetical units, orientated according to the pseudoaffine deformation mechanism.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1435-1536
    Keywords: Dichroism ; fluorescence polarization ; birefringence ; fluorescent probes ; polycarbonate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Bis-phenol-A-polycarbonate (PC) is dyed in solution with fluorescent molecules of different shapes and cast to films. Rectangular samples, cut from these films, are drawn varying draw ratio and drawing temperature. The orientation of the fluorescent probes is investigated by dichroism and fluorescence polarization, that of the polymer segments by birefringence. Hermans' orientation factors obtained by dichroism and fluorescence polarization are in good agreement. Long rodlike fluorescent molecules exhibit greater orientation factors than smaller ones. The correlation between segmental and probe orientation is discussed. Keeping the birefringence constant, the probe orientation factors depend on drawing temperature.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1435-1536
    Keywords: Dichroism ; fluorescence polarization ; birefringence ; fluorescent probes ; polystyrene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Atactic polystyrene (PS) is doped in solution with various fluorescent molecules and cast to films. Rectangular samples, cut from these films, are uniaxially drawn at 100 °C and 110 °C. The orientation of the fluorescent probes is characterized by UV-dichroism and fluorescence polarization, that of the polymer segments by IR-dichroism and birefringence. It is observed that the fluorescent molecules depending on their structure tend to orientate more or less perpendicular to the drawing direction. This can be understood by assuming that the benzene rings of the fluorescent probes try to associate to those of the polymer. As consistent values of the angle between the 2850 cm−1 transition moment and the chain axis and of the intrinsic birefringence result 70° and −0.10 respectively.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 259 (1981), S. 911-916 
    ISSN: 1435-1536
    Keywords: Dichroism ; fluorescent molecules ; orientation factor ; Polyvinylchloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Eine Reihe von Fluoreszenzmolekiilen unterschiedlicher Gestalt werden in PVC-Folien eingebettet. Die Folien werden bei 55 °C und 85 °C verstreckt. Mit Hilfe von UV-Dichroismus und Doppelbrechung werden Orientierungsmittelwerte für die Fluoreszenzmolekiile bzw. Polymersegmente bestimmt. Die Abhängigkeit der Orientierungsmittelwerte von Verstreckparametern und dem speziellen Fluoreszenzstoff wird diskutiert. Lange, stäbchenförmige Moleküle weisen höhere Orientierungswerte auf als kleinere. Die Summe der Absorptionskoeffizieten ist offenbar abhängig von der Temperatur des Verstreckungsprozesses.
    Notes: Summary Various fluorescent molecules of different shapes are imbedded in PVC-films. The films are drawn at 55 °C and 85 °C. The orientation factor of the fluorescent molecules and of the polymer segments are measured using UV-dichroism and birefringence respectively. The dependence of the orientation factors on drawing parameters and fluorescent species is discussed. Long rodlike fluorescent molecules exhibit gerater orientation factors than smaller ones. The sum of absorption coefficients turns out to depend on temperature of drawing process.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...