Quinoxaline Polymers and Copolymers Derived from 1,4-Bis(1'-Naphthalenyloxalyl)Benzene and Their Graphite Composites.
Abstract
Much work has been performed on the synthesis of polyquinoxalines, particularly on arylated quinoxaline polymers, for use as matrix materials for boron and graphite composites. Certain polyquinoxalines are valuable in such applications because, having attractive high temperature properties, they make possible extension of the temperature range of utilization of the composites further toward the ultimate capability of the reinforcement. Work on the polyphenylquinoxalines showed that polymers with high glass transition temperatures (in the order of 250-435 deg C) and high decomposition temperatures (in the order of 510-560 deg C) were obtainable. The oxidative resistance in air, as measured by weight loss in thermogravimetric analysis experiments or by isothermal aging at 371 deg C, was notable; introduction of oxygen linkages into the molecule, however, gave greater oxidative susceptibility in some polymers. On the other hand, the thermoplasticity of the polyphenylquinoxalines above their glass transition temperatures limits the range of their use for structural applications. Furthermore, some polyphenylquinoxaline form highly viscous solutions which wet reinforcing filaments with difficulty. These deficiencies affect adversely the use of these polymers in the preparation of laminates. jg p10
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1976
- Accession Number
- ADA305357
Entities
People
- William S. Port