Title: THERMOPLASTIC POLYIMIDES AND COMPOSITES THEREFROM
Inventor(s): F. Harris
Disclosure 138-DIV U.S. Patent 5,360,671
Disclosure 138-DIV-CIP U.S. Patent not yet issued
A new class polyimide and polyimide precursor based on diaryl oxyalkylene diamines, such as 1,3-bis[4-aminophenoxy]-2,2-dimethyl propane, a process for their preparation and their use as the continuous phase for the manufacture of composites and composite laminates reinforced by reinforcing agents such as carbon fiber, Kevlar and other similar high strength reinforcing agents. The polyimides and molecular composites obtained from the diamines according to the invention show thermoplastic properties, excellent flex fatigue and fracture resistance, and excellent thermal and oxidative stability.
This technology provides a new way to make composites, which typically could only be compression molded, processable by less dramatic means through the incorporation of a reactive plasticizer. This technology is suitable for the manufacture of shaped articles of very diverse types, such as fibers, films, sheets, coatings, foams, laminates, molding powders, press articles and the like. The composites may be formed by any technique which is generally known in the art such as compression molded, autoclaving, injection molding, etc.
Applications that samples were prepared and tested for were (1) the next generation fan blades for aircraft (panels were 100 ply laminates), and (2) High Speed Civil Transport Car and\or Fast Rail Car. Prior to product commercialization incorporating this technology, the composite market bottomed out in 1991/92 time frame and major new products were cancelled by both industry and government. The same and similar type applications remain viable today for this technology.
Title: POLYIMIDES COMPRISING SUBSTITUTED BENZIDINES
Inventor(s): F. Harris
Disclosure 126 U.S. Patent 5,071,997
A new class of polyimides and copolyimides made from substituted benzidines, aromatic dianhydrides and other aromatic diamines. The polyimides obtained with said diamines are distinguished by excellent thermal, soluble, and electrical properties (such as very low dielectric constants), excellent clarity and mechanical properties.
These polyimides are ideally suited as coating materials for microelectronic apparatii, as membranes for selective molecular or gas separation, as fibers in molecular composites, as high tensile strength, high compression strength fibers, as film castable coatings, or as fabric components.