Abstract: Structures having anodized aluminum surfaces are coated with corrosion blocking fatty acid coatings by dipping successive portions of the structures progressively through a layer of fatty acid disposed on a liquid in a tank and into the liquid which bodily receives the structure, to achieve effective sealing coating without the use of large volumes of fatty acid.

Abstract: Aluminum surfaces are protected with increased corrosion resistance by anodize, and sealing with a liquid fatty acid free of flammable solvents, suitably in the presence of a heterocyclic aromatic azole treating agent where the aluminum surface is of a copper containing aluminum alloy.

Abstract: A hole repair method and composition suitable for mufflers, and engine exhaust systems, and any situation where high temperature resistance is needed. A putty like mass of polyimide resin and from 28% to 35% of low boiling alcohol is used to fill the hole, then foamed by heating into a mechanically seated and adherent plug which is high temperature resistant and securely in place.

Abstract: A hole repair method and composition suitable for mufflers, and engine exhaust systems, and any situation where high temperature resistance is needed. A putty like mass of polyimide resin and from 28% to 35% of low boiling alcohol is used to fill the hole, then foamed by heating into a mechnically seated and adherent plug which is high temperature resistant and securely in place.

Abstract: A high temperature, flame resistant polyimide foam material and methods of making open and closed cell, rigid and flexible foams from common precursors. An aromatic tetracarboxylic dianhydride is reacted with an amino and an alcohol or mixtue of alcohols to produce an N-substituted imido acid ester. The product is then reacted with an aromatic diamine. The resulting liquid is dried, ground to a course powder, and classified into sizes from 0.25 mm to 2 mm by sieving. The powder is suitable for foaming without further modification, by expansion at 100 to 3000 in a closed mold to form a well consolidated, uniform, mostly closed cell product. When expanded unrestrictedly, open cell flexible or rigid consolidated foams are produced, depending on choice of alcohol(s). The foams have excellent resistance to heat and flame, and bond well to glass prepreg to form rigid structures.

Abstract: A high temperature, flame resistant polyimide foam material and methods of making open and closed cell, rigid and flexible foams from common precursors. An aromatic tetracarboxylic dianhydride is reacted with an amino acid and an alcohol or mixture of alcohols to produce an N-substituted imido acid ester. The product is then reacted with an aromatic diamine. The resulting liquid is dried, ground to a course powder, ad classified into sizes from 0.25 mm to 2 mm by sieving. The powder is suitable for foaming without further modificaiton, by exapansion at 100 to 3000 in a closed mold to form a well consolidated, uniform, mostly closed cell product. When expanded unrestrictedly, open cell flexible or rigid consolidated foams are produced, depending on choice of alcohol(s). The foams have excellent resistance to heat and flame, and bond well to glass prepreg to form rigid structures.

Abstract: A high temperature, flame resistant polyimide foam material and methods of making open and closed cell, rigid and flexible foams from common precursors. An aromatic tetracarboxylic dianhydride is reacted with an amino acid and an alcohol or mixture of alcohols to produce an N-substituted imido acid ester. The product is then reacted with an aromatic diamine. The resulting liquid is dried, ground to a course powder, and classified into sizes from 0.25 mm to 2 mm by sieving. The powder is suitable for foaming without further modification, by expansion at 100 to 3000 in a closed mold to form a well consolidated, uniform, mostly closed cell product. When expanded unrestrictedly, open cell flexible or rigid consolidated foams are produced, depending on choice of alcohol(s).