Fluorescence depolarization in polymers: The microviscosity of bulk polybutadiene and of solutions in cyclohexane

✍ Scribed by Barkowski, D. ;Mersch, W. ;Dorfmüller, Th.

• Book ID: 105334156
• Publisher: Wiley (John Wiley & Sons)
• Year: 1982
• Tongue: English
• Weight: 388 KB
• Volume: 20
• Category: Article
• ISSN: 0098-1273
• DOI: 10.1002/pol.1982.180200603

✦ Synopsis

Abstract

The reorientational relaxation of 9‐cyananthracene fluorescent label molecules has been measured in bulk polybutadiene and solutions with cyclohexane by a fluorescent depolarization technique. The procedure adopted consists in the incorporation of an Arrhenius temperature dependence of the orientational relaxation time in the Perrin equation, thus obviating the necessity of an independent determination of the intrinsic polarization ratio P~0~ and enabling one to obtain the preexponential factors and the activation energies of the reorientational relaxation times. The most noteworthy result in our view is the validity of the Arrhenius equation for the effective microviscosity as opposed to the validity of the Fulcher–Vogel–Tamann equation with a glass point of T~0~ = 136 K for the shear viscosity of a polymer solution (90%).