Michael addition reactions in macromolecular design for emerging technologies

Introduction to Nanotechnology

A method for manufacturing a conductive composition comprises blending a polymer precursor with a single wall carbon nanotube composition; and polymerizing the polymer precursor to form an organic polymer. The method may be advantageously used for manufacturing automotive components, computer components, and other components where electrical conductivity properties are desirable.

Electrically conductive compositions and method of manufacture thereof

A transparent and conductive film comprising at least one network of graphene flakes is described herein. This film may further comprise an interpenetrating network of other nanostructures, a polymer and/or a functionalization agent(s). A method of fabricating the above device is also described, and may comprise depositing graphene flakes in solution and evaporating solvent therefrom.

Graphene film as transparent and electrically conducting material

Polyimides from 2,3,3′,4′-biphenyltetracarboxylic dianhydride and aromatic diamines

Spacecraft with electrostatic dissipative surfaces are disclosed herein. The surface has layer which includes a plurality of carbon nanotubes to incorporate electrical conductivity into space durable polymeric layers without degrading optical transparency, solar absorptivity or mechanical properties.

Esd coatings for use with spacecraft

A composition of and method for making high performance imide resins that are processable by resin transfer molding (RTM) and resin infusion (RI) techniques were developed. Materials with a combination of properties, making them particularly useful for the fabrication of composite parts via RTM and/or RI processes, were prepared, characterized and fabricated into moldings and carbon fiber reinforced composites and their mechanical properties were determined. These materials are particularly useful for the fabrication of structural composite components for aerospace applications. The method for making high performance resins for RTM and RI processes is a multi-faceted approach. It involves the preparation of a mixture of products from a combination of aromatic diamines and aromatic dianhydrides at relatively low calculated molecular weights (i.e. high stoichiometric offsets) and endcapping with latent reactive groups. The combination of these monomers results in a mixture of products, in the imide form, that exhibits a stable melt viscosity of less than approximately 60 poise below approximately 300 °C.

Composition of and method for making high performance resins for infusion and transfer molding processes

Controlled molecular weight imide oligomers and co-oligomers containing pendent phenylethynyl groups (PEPIs) and endcapped with nonreactive or phenylethynyl groups have been prepared by the cyclodehydration of the precursor amide acid oligomers or co-oligomers containing pendent phenylethynyl groups and endcapped with nonreactive or phenylethynyl groups. The amine terminated amide acid oligomers or co-oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and diamine containing pendent phenylethynyl groups and subsequently endcapped with a phenylethynyl phthalic anhydride or monofunctional anhydride. The anhydride terminated amide acid oligomers and co-oligomers are prepared from the reaction of diamine(s) and diamine containing pendent phenylethynyl group(s) with an excess of dianhydride(s) and subsequently endcapped with a phenylethynyl amine or monofunctional amine. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone and N,N-dimethylacetamide under nitrogen at room temperature. The amide acid oligomers or co-oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. The polymers and copolymers prepared from these materials exhibit a unique and unexpected combination of properties that includes higher glass transition temperatures after curing and higher retention of neat resin, adhesive and carbon fiber reinforced mechanical properties at temperatures up to 204 °C under wet conditions without sacrificing melt flow behavior and processability as compared to similar materials. These materials are useful as adhesives, coatings, films, moldings and composite matrices.

Imide oligomers and co-oligomers containing pendent phenylethynyl groups and polymers therefrom

Phenylethynyl containing imide-silanes were prepared from aminoalkyl and aminoaryl alkoxy silanes and 4-phenyletbynylphthalic anhydride in toluene to form the imide in one step or in N-methyl-2-pyrrolidinone (NMP) to form the amide acid intermediate. Controlled molecular weight pendent phenylethynyl amide acid oligomers terminated with aminoaryl alkoxy silanes were prepared in NMP from aromatic dianhydrides, aromatic diamines, diamines containing pendent phenylethynyl groups and aminoaryl alkoxy silanes. The phenylethynyl containing imide-silanes and controlled molecular weight pendent phenylethynyl amide acid oligomers terminated with aminoaryl alkoxy silanes were used to improve the adhesion between phenylethynyl containing imide adhesives and inorganic substrates (i.e. metal). Hydrolysis of the alkoxy silane moiety formed a silanol functionality which reacted with the metal surface to form a metal-oxygen-silicon (oxane) bond under the appropriate reaction conditions. Upon thermal cure, the phenylethynyl group of the coupling agent reacts with the phenylethynyl functionality of phenylethynyl containing imide adhesives and becomes chemically bonded to the matrix. The resultant adhesive bond is more durable (i.e. hot-wet environmental resistance) than adhesive bonds made without the use of the coupling agent due to covalent bond formation between the phenylethynyl containing imide-silane coupling agent or the controlled molecular weight pendent phenylethynyl amide acid oligomers terminated with aminoaryl alkoxy silanes and both the metal substrate and phenylethynyl containing imide adhesives.

Phenylethynyl-containing imide silanes

Ethynyl terminated imidothioethers (ETIs) are prepared by the reaction of a dimercaptan, such as 4,4'-dimercaptodiphenyl ether, and an ethynyl containing maleimide, such as N-(3-ethynylphenyl)maleimide. Blends of these ETIs and ethynyl terminated polymeric materials, such as ethynyl terminated sulfones and ethynyl terminated arylene ethers, are also prepared. These resin blends exhibit excellent processability, and the cured blends show excellent fracture toughness and solvent resistance, as well as excellent adhesive and composite properties.

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John W. Connell

Papers

Esd coatings for use with spacecraft

Composition of and method for making high performance resins for infusion and transfer molding processes

Imide oligomers and co-oligomers containing pendent phenylethynyl groups and polymers therefrom

Phenylethynyl-containing imide silanes

Ethynyl terminated imidothioethers and resins therefrom