Accession Number:

ADA305357

Title:

Quinoxaline Polymers and Copolymers Derived from 1,4-Bis(1'-Naphthalenyloxalyl)Benzene and Their Graphite Composites.

Descriptive Note:

Final rept. 7 Feb 75-30 Apr 76,

Corporate Author:

AVCO CORP LOWELL MA SYSTEMS DIV

Personal Author(s):

Report Date:

1976-07-01

Pagination or Media Count:

100.0

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

Subject Categories:

  • Polymer Chemistry
  • Organic Chemistry
  • Physical Chemistry
  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE