Molecular Level Composite of PBT/ABPBI: Phase Relationships, Processing and Properties
Abstract
The concentrated solution phase relationships and bulk polymer morphology of a solvent/rigid rod/flexible coil system were investigated. The solvent was a mixture of two strong acids. The rigid rod polymer was poly-para- phenylene-benzbisthiazole (PBT). The flexible coil polymer was poly-2,5(6) benzimidazole (ABPBI). The concentrated solution and bulk polymer morphologies were investigated by means of polarized optical microscopy, small angle light scattering, scanning electron microscopy, and a wide angle x-ray diffraction techniques. Above a critical concentration, Ccr, the pseudo ternary solution separated into two coexisting phases, one optically anistropic (liquid crystalline) and the other isotropic. The anistropic domains were highly birefringent. They contained primarily the PBT macromolecules oriented preferentially along a domain axis. Numerical results of Ccr, determined experimentally, were in good agreement with calculated predictions. Aggregates composed of PBT molecules were observed to be dispersed in a continuous matrix for vacuum cast films. These results strongly indicate the dominance of entropic effects in the thermodynamics of rigid rod-like polymer flexible coil-like polymer mixtures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1982
- Accession Number
- ADA122059
Entities
People
- C. Benner
- D. Wiff
- G. Price
- T. Helminiak
- W. F. Hwang
Organizations
- Wright Laboratory