NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Time-Domain Dielectric Spectroscopy Analysis of the Amorphous Phase in Semicrystalline Polycarbonate
Published
Author(s)
Chad R. Snyder, F I. Mopsik, H Marand, S M. Sohn
Abstract
The amorphous state of bisphenol-A polycarbonate was examined by time-domain dielectric spectroscopy as a function of crystallization time over a frequency range of 1 x 10-4 Hz to 1 x 104 Hz. The dielectric measurements were performed in the temperature range around the glass transition temperature. Dielectric studies were performed on a series of samples, which were partially melted and recrystallized so as to investigate the influence of secondary crystallinity on the alpha relaxation, thereby probing the effect of crystalline constraints on cooperative motions in the amorphous fraction. Analysis of the relaxation behavior was performed by fitting the loss max frequency data to the Vogel-Fulcher-Hesse-Tammann and Arrhenius equations. Fits to the Havriliak-Negami equation were performed with careful consideration of the conclusions made by two of us in a recent paper: C.R. Snyder and F.I. Mopsik, J. Appl. Phys., 84 (8), 4421 (1998).
Snyder, C.
, Mopsik, F.
, Marand, H.
and Sohn, S.
(1999),
Time-Domain Dielectric Spectroscopy Analysis of the Amorphous Phase in Semicrystalline Polycarbonate, ASC Technical Conference, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851636
(Accessed October 2, 2025)