Low-Melt Poly(Amic Acids) and Polyimides and their Uses
AssigneesUnited States of America as represented by the Administrator of the National Aeronautics and, Space Administration
InventorsScott T. Jolley, Tracy L. Gibson, Martha K. Williams, Clyde F. Parrish, Steven L. Parks
Life of this patent
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Abstract
Provided are low-melt polyimides and poly(amic acids) (PAAs) for use in repair of electrical wire insulation, flat or ribbon wire harnesses, and flat surfaces comprised of high-performance polymers such as inflatables or solar panels applications. Also provided are methods and devices for repair of electrical insulation.
Claims50
A method of repairing a substrate comprising:
- (a) obtaining a substrate having continuous or discontinuous layer of a low-melt polymer outside of and in contact with the substrate, or applying a continuous or discontinuous layer of a low-melt polymer to a substrate;
- (b) heating the layer of a low-melt polymer to a first temperature effective to melt the low-melt polymer to spread it into cracks or deformations that may exist or have formed in the substrate;
- and
- (c) heating the layer of a low-melt polymer to a second temperature effective to cross-link the low-melt polymer and to repair the cracks or deformations in the substrate;
- wherein the low-melt polymer comprises a poly(amic acid) (PAA) or a polyimide.
A method of repairing a substrate comprising:
- (a) obtaining a substrate and a continuous or discontinuous layer of a low-melt polymer in contact with the substrate, or applying a continuous or discontinuous layer of a low-melt polymer to a substrate;
- and
- (b) heating the layer of a low-melt polymer to a first temperature effective to melt the low-melt polymer to spread it into cracks or deformations that may exist or have formed in the substrate;
- wherein the low-melt polymer comprises a polyimide comprising polyether or polysiloxane blocks.
A wire insulation repair wrap comprising a poly(amic acid) (PAA) or a polyimide having reactive end groups, or a polyimide comprising polyether blocks or polysiloxane blocks;
- wherein the wrap is adapted to patch or surround an electrical wire having a layer of polyimide insulation, so as to repair damage to the insulation layer.
An article of manufacture comprising a metal layer coated with a coating comprising a polyimide;
- wherein the coating is formed by a process comprising:
- coating the metal with a low-melt polymer comprising reactive end caps, wherein the low-melt polymer is a polyimide or poly(amic acid) (PAA);
- and
- heating the low-melt polymer on the metal to initiate cross-linking on the metal to form a high-melt polyimide coating.
A method of forming a polymer coating on a metal comprising:
- coating the metal with a low-melt polymer comprising olefinic organic acid end caps, wherein the low-melt polymer is a polyimide or poly(amic acid) (PAA);
- and
- heating the low-melt polymer on the metal to initiate cross-linking on the metal to form a high-melt polyimide coating.
A method of forming a polyimide film or poly(amic acid) (PAA) film comprising:
- obtaining a solution of a polyimide or a PAA in an organic solvent;
- casting the solution on a non-stick surface selected from a polysiloxane and a perfluorinated alkane;
- evaporating at least a portion of the organic solvent from the solution on the surface to form a polyimide film or a PAA film.
A low-melt polymer comprising olefinic organic acid end caps, having an average molecular weight below 20,000, and having a melting temperature below 300° C., wherein the low-melt polymer is a polyimide or poly(amic acid) (PAA).
A method of forming a molded article of manufacture comprising:
- obtaining a polymide having a melting temperature below 300° C.;
- melting the polyimide;
- forming the melted polyimide into a desired shape by injection molding, extrusion molding, rotomolding, blow molding, or vacuum forming;
- curing the polyimide in the desired shape into a higher melting temperature polyimide by heating the polyimide further past the curing temperature and allowing the polyimide to cure for an effective time at a temperature above the curing temperature;
- and
- cooling the cured polyimide in the desired shape.
A method of forming a polyimide comprising:
- reacting a dianhydride and a diamine in a polymerization reaction mixture to form a poly(amic acid) (PAA);
- and
- heating the PAA to form a polyimide;
- wherein the dianhydride is a dianhydride of formula 1,
- wherein each R1 is independently H or (C1-C4)alkyl, and each R2 is independently H or (C1-C4)alkyl or CF3;
- or wherein the diamine is a diamine of formula 2 or 3
- H2N—(C2-C6)alkyl-[O—(C2-C6)alkyl-]nO—(C2-C6)alkyl-NH2 (2)
- H2N—(C2-C6)alkyl-O—Si(CH3)2—[O—Si(CH3)2—]nO—Si(CH3)2—O—(C2-C6)alkyl-NH2 (3)
- wherein at least 50% by weight of reactants in the polymerization reaction mixture are a compound of formula 1, 2, or 3 or a combination thereof.
A method of forming a poly(amic acid) (PAA) comprising:
- reacting a dianhydride and a diamine in a polymerization reaction mixture to form a PAA;
- wherein the dianhydride is a dianhydride of formula 1,
- wherein each R1 is independently H or (C1-C4)alkyl, and each R2 is independently H or (C1-C4)alkyl or CF3;
- or wherein the diamine is a diamine of formula 2 or 3
- H2N—(C2-C6)alkyl-[O—(C2-C6)alkyl-]nO—(C2-C6)alkyl-NH2 (2)
- H2N—(C2-C6)alkyl-O—Si(CH3)2—[O—Si(CH3)2—]nO—Si(CH3)2—O—(C2-C6)alkyl-NH2 (3)
- wherein at least 50% by weight of reactants in the polymerization reaction mixture are a compound of formula 1, 2, or 3 or a combination thereof.
Dependencies are inferred from the claim text.