The United States of America As Represented by the Administrator of the

Stephen S Tompkins

John W Connell

Timothy W Towell

Gregory A Dries

Films of thermoplastic poly(arylene ether imidazole)s (PAEI)s are used as surface modifiers for neat resin panels and composite resin panels. The PAEI polymer contains imidazole groups along the backbone which co-cure, i.e., react chemically, with epoxies or bismaleimides during processing and thereby provide excellent adhesion between the PAEI film and an epoxy or bismaleimide neat resin or composite resin facesheet. The film provides good adhesion and a smooth surface to the finished part and acts as a release agent from the mold. The as-processed integral structures have very smooth (specular) surfaces, and since the film releases readily from a glass mold, no release agent is necessary. The PAEI film is thermally stable, resistant to electron radiation, and adheres tenaciously to the facesheet. The film maintains good adhesion even after thermal cycling from room temperature to .about. -196.degree. C.

Poly(arylene ether imidazole) surfacing films for flat and parabolic

A method is disclosed for treating graphite reinforced metal matrix composites so as to eliminate thermal strain hysteresis and impart dimensional stability through a large thermal cycle. The method is applied to the composite post fabrication and is effective on metal matrix materials using graphite fibers manufactured by both the hot roll bonding and diffusion bonding techniques. The method consists of first heat treating the material in a solution anneal oven followed by a water quench and then subjecting the material to a cryogenic treatment in a cryogenic oven. This heat treatment and cryogenic stress reflief is effective in imparting a dimensional stability and reduced thermal strain hysteresis in the material over a -250.degree. F. to +250.degree. F. thermal cycle.

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Williamsburg, VA, United States of America

Stephen S Tompkins