Dielectric relaxation of polar aromatics in unoriented and oriented linearlow-density polyethylene

The dielectric behavior of some polar aromatics dissolved in nonpolar unori ented and stretched linear low-density polyethylene was investigated within the temperature region between 150 and 350 K. The measurements were carrie d out in the frequency range 1 kHz to 10 MHz. The maximum temperatures and the half widths of the loss tangent peaks depend upon the shape and the pol ar structure of guest molecules. Stretching the samples induced a shift of the loss tangent to higher temperatures, decreased the height, and increase d the width of tan delta peak. The activation energy is also influenced by the type of guest molecules and orientation of polymer matrix. (C) 2000 Joh n Wiley & Sons, Inc.