HIGH-TEMPERATURE STRUCTURAL ADHESIVES.
Final summary rept. for 1 Mar 63-15 Apr 64,
WHITTAKER CORP SAN DIEGO CALIF NARMCO RESEARCH AND DEVELOPMENT DIV
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This report concerns the synthesis of polymers possessing hydrolytic, oxidative, and thermal stability which are potentially useful as structural adhesives and laminating resins. The four systems investigated were the polyimides, polybenzothiazoles, polyquinoxalines, and polythiazolothiazoles. Synthetic emphasis was concentrated on condensation reactions in which the formation of the heterocyclic ring created the polymer chains. To achieve thermal stability, the heterocyclic rings were linked together through arylene units. A major portion of the program involved the synthesis of prepolymers of sufficiently low molecular weight to permit good solubility and fusibility which upon further condensation gave high molecular weight, thermally stable polymers. Solubilizing moieties such as diphenyl ether, benzophenone, pyridine, and diphenyl sulfone were incorporated in the polymer chain in an attempt to improve processability. The course of the reactions was followed by performing physical measurements such as inherent viscosity, specific extinction coefficient, thermal gravimetric analysis TGA, glass transition temperature Tg, and changes in infrared spectra. Selected polymeric systems were evaluated for potential use as structural laminates and adhesives by fabricating laminates, usually 2-ply, and tensile shear specimens. Author