Spectroscopic Analysis of Electrically Polarized Poly(Acrylonitrile).
Abstract
Electrically polarized and unpolarized films of poly(Acrylonitrile) have been investigated by both infrared attenuated total reflection (ATR) and thermally stimulated discharge (TSD). ATR analysis of PAN films has been aimed at explaining the molecular origin of thermally stimulated currents, and consequently that of phenomena contributing to electrical polarization in this material. Preferred orientation of nitrile dipoles along the thickness direction (applied electric field direction) has been detected by ATR in both polarized and unpolarized films. It is suggested that dipolar alignment in unpolarized solvent cast films results from internal electric fields associated with space charges. The observed orientational anisotropy is found to disappear gradually as films (both polarized and unpolarized) are heated from ambient temperature to 100 C and rotational motion in the backbone is thermally activated. tsd currents observed in this thermal range are thus associated with randomization of molecular dipoles. TSD currents observed above 100 C are suggested to originate from drift of space charges, since both an isotropic orientation of dipoles and onset of considerable diffusion are detected by ATR in this temperature range.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 20, 1977
- Accession Number
- ADA035859
Entities
People
- S. H. Carr
- Samuel I. Stupp
Organizations
- Northwestern University