Brillouin and Rayleigh Scattering in Polybutadiene.

Abstract

The molecular light scattering of polybutadiene from 110 to 350K was carried out. The study includes the measurements of Brillouin shift, Brillouin linewidth and Rayleigh depolarization ratios as a function of temperature. It has been found that the hypersonic frequency displays a discontinuity at the glass temperature Tg. The hypersonic attentuation coefficient over one wavelength has also been determined as a function of temperature. No quantitative theory has been found to be able to describe the sound attenuation above Tg. The Krishnan effect was also observed below 250K. This is the first experiment which observes the evolution of the Krishnan effect. It has been pointed out that the frozen-in density fluctuation mechanism fails to explain the effect. The frozen-in fluctuations of the dielectric anisotropy is suggested to be a possible mechanism for the Krishnan effect. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Mar 22, 1974
Accession Number
AD0776665

Entities

People

  • C. H. Wang
  • Y. Y. Huang

Organizations

  • University of Utah

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Anisotropy
  • Attenuation
  • Coefficients
  • Depolarization
  • Discontinuities
  • Electromagnetic Radiation
  • Electromagnetic Scattering
  • Frequency
  • Light Scattering
  • Measurement
  • Polybutadiene
  • Rayleigh Scattering
  • Scattering
  • Synthetic Rubber

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Materials Science and Engineering.
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Boundary Layers
  • Hypersonics - Hypersonic Flight