E.i. Dupont De Nemours and Company

Thomas P Gannett

Robert J Kassal

Hugh H Gibbs

Richard J Boyce

Brian C Auman

Alan Martin Allgeier

Julius Uradnisheck

David P Higley

Murty S Tanikella

Rolland Shin-Yuan Ro

James M Sonnett

Kelley Moran Whittle

Willard J Jones

Porous infusible polymer (IP) parts are made by incorporating 0.2 to 10 volume percent organic fibers, preferably with short lengths, into the particulate IP, consolidating the mixture under pressure and optionally heating, and then 'burning off' the fibers. After the fibers are burned off the resulting part has porosity in which the pores are elongated, usually retaining the shape of the organic fibers. When these parts are exposed to moisture (which they usually absorb) and then suddenly heated they tend not to blister from vaporization of the water. This makes them useful as parts for aircraft (jet) and other engines and other applications where sudden temperature increase may occur.

Porous infusible polymer parts

Disclosed is a method for preparing tertiary amine compounds from primary amines and nitrites in the presence of hydrogen gas and a metal catalyst, or metal-containing catalyst composition, at a temperature from about 50&deg; C. to about 200&deg; C. and at a pressure from about 100 psig to 1500 psig. The primary amines and the nitriles used in the process may be diamines and/or dinitriles, or may be combinations of primary amines and/or nitrites. Also disclosed are novel tertiary amine compounds made by the described method.

Process for the preparation of tertia&racute;y amines from primary amines and nitriles

Copolyimides from 1,4-bis(4-aminophenoxy)-2-phenylbenzene and m- or p-phenylene diamine with biphenyl dianhydride exhibit a high Tg and reduced melt viscosity.

Melt-processible polyimides with high Tg

Low void composites with high Tg polyimide matrices are prepared from stoichiometrically unbalanced precursors.

Process for preparing polyimide composites

Melt-fusible copolyimides based on pyromellitic anhydride and two defined classes of aromatic diamines, at least one diamine of each class being incorporated into the polyimide, each diamine class being present in an amount of 10-90 mole percent of the total diamine content (100 mole percent), melt below about 400.degree. C. and can be fabricated into articles, or can be applied to either fibrous or nonfibrous substrates to make prepregs, tapes, etc., which then are shaped into final articles, such as printed circuit boards or aircraft panels.

Melt-fusible co-polyimide from diamine mixture

Melt-fusible polyimides based on pyromellitic dianhydride and at least one defined aromatic diamine are useful in making low-void composites and thermoplastic tapes, which can be fabricated into articles such as, for example, aircraft and autobody panels, printed circuit boards, etc. Some of these polyimides are melt-processible and can be fabricated by conventional procedures such as extrusion and injection molding.

Melt-fusible polyimides

A process for preparing a symmetrical dinitrodiphenyl ether from o- or p-nitrochlorobenzene or o- or p-nitrofluorobenzene comprising using a polar organic solvent, a potassium salt of a fatty carboxylic acid containing 2 to 20 carbon atoms or a potassium salt of an aromatic carboxylic acid containing 7 to 12 carbon atoms as catalyst, and either sodium or potassium carbonate to react with the p-nitrochlorobenzene. The reaction is carried out at from 150.degree. to 210.degree. C. until the o- or p-nitrochlorobenzene or o- or p-nitrofluorobenzene reacts.

Production of dinitrodiphenyl ether

Melt-fusible polyimides based on pyromellitic dianhydride and 2,2-bis[3,5-dichloro-4-(4-aminophenoxy)phenyl]propane, alone or in combination with other defined diamines, are useful in making low-void composites and thermoplastic tapes, which can be fabricated into articles such as, for example, aircraft and autobody panels, printed circuit boards, etc.

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Wilmington, DE, United States of America

Thomas P Gannett