Quinoxaline Ladder Polymers for High Temperature Laminating Resins and Structural Adhesives.
Annual rept. 1 Jun 67-31 May 68,
HUGHES AIRCRAFT CO CULVER CITY CA AEROSPACE GROUPS
Pagination or Media Count:
Quinoxaline ladder polymers were prepared by the condensation polymerization of 2,3-deiphenoxy-6,7-diaminoquinoxaline. Fusible and soluble prepolymers were synthesized by melt polymerization, and varnishes made with dimethylformamide were used to coat glass cloth reinforcement and to fabricate laminates. The molded parts were postcured at temperatures up to 750F 399C. Elemental analyses indicated that the polymer was either a high molecular weight polymer with about 60 to 80 percent of the rings closed to form the ladder structure, or more probably, a comparatively low molecular weight polymer with a higher percentage of ring closure within the polymer chains. The relatively low flexural strength of the laminates was attributed to the low molecular weight. The thermal stability in an inert atmosphere matched that of the best quinoxaline ladder polymers synthesized by Marvel. However, the stability in an isothermal weight loss test in air at 700F 371C was unsatisfactory. A resin was obtained by the condensation of 1,2,4,5-tetraaminobenzene and 2,3,7,8-tetraphenoxy-1,4,6,9-tetraazaanthracene. Fusible prepolymers suitable for molding were synthesized in m-cresol. The thermal properties of the cured resin were similar to those of the polymer derived from diphenoxydiaminoquinoxaline. Author
- Physical Chemistry
- Polymer Chemistry
- Adhesives, Seals and Binders