Abstract: A high-temperature polymeric-matrix composite (HTPMC) structure and a method for protecting an HTPMC from exposure to high temperatures in the presence of air, and prevent thermo-oxidative degradation. A thin, lightweight layer of a carbon-based barrier is applied onto a surface of the HTPMC structure. The carbon-based barrier coating is composed of graphene, amorphous carbon, or a mixture comprising a combination of graphene and amorphous carbon, and has coefficient of thermal expansion that is less than 10 times the coefficient of thermal expansion of the HTPMC structure. The carbon-based barrier may be coated with an erosion-barrier.

Abstract: A method of making a coated polymer-matrix composite (PMC) having high-temperature oxidation protection includes bonding a first surface of a flexible sublayer that is free of water to a first surface of a dry PMC substrate having a first coefficient of thermal expansion. The flexible sublayer includes an electrically conductive material in an effective amount to enable electrical conductivity of the flexible sublayer, and includes a low-modulus-of-elasticity material. The method includes heating the bonded flexible sublayer and the PMC substrate, and bonding a first surface of an oxygen-impervious, dense barrier-coating layer to a second surface of the flexible sublayer to form the coated PMC having high-temperature oxidation protection.

Abstract: Materials and methods are provided for producing preform materials for impact-resistant composite materials suitable for liquid molding. Interlayers formed of nonwoven, continuous fibers, such as spunbonded, spunlaced, or mesh fabric, are introduced between non-crimped layers of unidirectional reinforcing fibers to produce a preform for use in liquid-molding processes to produce a composite member. Curing of the preform provides increased impact resistance by increasing the amount of energy required to propagate localized fractures due to impact.

Abstract: Water-entrained compositions comprising colloidal or suspensoidal solutions comprising polyimide pre-polymers/oligomers are described. These compositions are obtained in water by initial dispersion of the resin constituents in water to from colloids or suspensoids. The water-entrained polyimide compositions can be applied to numerous surfaces or more beneficially used for composite fabrication. The coated surfaces or polyimide-pre-polymer impregnated reinforcing materials are subsequently cured and are ideal for providing thermal protection.

Abstract: The present invention relates to a continuous, carbon fiber with nanoscale features comprising carbon and carbon nanotubes, wherein the nanotubes are substantially aligned along a longitudinal axis of the fiber. Also provided is a polyacrylonitrile (PAN) precursor including about 50% to about 99.9% by weight of a melt-spinnable PAN and about 0.01% to about 10% of carbon nanotubes. Other precursor materials such as polyphenylene sulfide, pitch and solution-spinnable PAN are also provided. The precursor can also include a fugitive polymer which is dissociable from the precursor polymer.

Abstract: A method and apparatus for manufacturing. A fiber layer and a first porous bonding layer are formed to form a unidirectional lay-up of fibers. The unidirectional lay-up of fibers is heated under pressure to form a unidirectional composite tape. A first plurality of lengths of the unidirectional composite tape is laid down to build a first layer from the unidirectional composite tape. A second plurality of lengths of the unidirectional composite tape is laid down to build a second layer from the unidirectional composite tape on the first layer at a predetermined angle from the first layer. At least one of the first and second plurality of lengths of the unidirectional composite tape are slit while laying down the first and second plurality of lengths of the unidirectional composite tape. A composite fabric is formed from the first and second layer.

Abstract: A composite structure and method of assembling a composite structure is provided. The composite structure includes a base member having an outer surface and an inner surface. The inner surface defines a channel therethrough. The composite structure further includes a support member coupled to the outer surface. A fabric overwrap is coupled to the support member.

Abstract: There is provided a fiber and method of making a fiber. The fiber has an inner-volume portion having a first outer diameter, a plurality of nanostructures, and one or more first polymers. The nanostructures act as an orientation template for orientation of the one or more first polymers in a direction parallel to a longitudinal axis of the fiber. The fiber has an outer-volume portion having a second outer diameter and one or more second polymers. The outer-volume portion is in contact with and completely encompasses the inner-volume portion. The inner-volume portion has at least one of a tensile modulus and a strength that are higher than at least one of a tensile modulus and a strength of the outer-volume portion.

Abstract: There is provided a hollow fiber and method of making. The hollow fiber has an inner-volume portion having a first-core portion and one or more hollow second-core portions. The first-core portion has nanostructures and one or more first polymers. The nanostructures act as an orientation template for orientation of the first polymers in a direction parallel to a longitudinal axis of the fiber. The first-core portion is in contact with and encompasses the hollow second-core portions. The hollow fiber further has an outer-volume portion having one or more second polymers. The outer-volume portion is in contact with and completely encompasses the inner-volume portion. The inner-volume portion has at least one of a tensile modulus and a strength that are higher than at least one of a tensile modulus and a strength of the outer-volume portion.

Abstract: A method of forming a preform may include providing a layer of tackified fibrous material containing structural fibers and resin. The layer may be passed through a forming die set having a die cross-sectional shape. The thermoplastic resin may be heated. The layer may be formed into the die cross-sectional shape. The thermoplastic resin may be allowed to solidify in a manner such that a preform is formed having the die cross-sectional shape.

Abstract: The present invention relates to a continuous, carbon fiber with nanoscale features comprising carbon and carbon nanotubes, wherein the nanotubes are substantially aligned along a longitudinal axis of the fiber. Also provided is a polyacrylonitrile (PAN) precursor including about 50% to about 99.9% by weight of a melt-spinnable PAN and about 0.01% to about 10% of carbon nanotubes. Other precursor materials such as polyphenylene sulfide, pitch and solution-spinnable PAN are also provided. The precursor can also include a fugitive polymer which is dissociable from the precursor polymer.

Abstract: A method and apparatus for manufacturing. A fiber layer and a first porous bonding layer are formed to form a unidirectional lay-up of fibers. The unidirectional lay-up of fibers is heated under pressure to form a unidirectional composite tape. A first plurality of lengths of the unidirectional composite tape is laid down to build a first layer from the unidirectional composite tape. A second plurality of lengths of the unidirectional composite tape is laid down to build a second layer from the unidirectional composite tape on the first layer at a predetermined angle from the first layer. At least one of the first and second plurality of lengths of the unidirectional composite tape are slit while laying down the first and second plurality of lengths of the unidirectional composite tape. A composite fabric is formed from the first and second layer.

Abstract: A method and apparatus for manufacturing. A fiber layer and a porous bonding layer are formed to form a unidirectional lay-up of fibers. The lay-up of fibers is heated under pressure to form a unidirectional composite tape of desired thickness to substantially maintain the fibers in a desired configuration. The unidirectional composite tape is slit to a desired width, and the slit unidirectional composite tape is loaded into a multiaxial fabric machine. A first layer is built from the composite tape in the multiaxial machine, and a second layer is built from the composite tape on the first layer at a predetermined angle from the first layer in the multiaxial machine. The first and second layers are consolidated to form a composite fabric in a continuous process.

Abstract: Materials and methods are provided for producing preform materials for impact-resistant composite materials suitable for liquid molding. Interlayers formed of nonwoven, continuous fibers, such as spunbonded, spunlaced, or mesh fabric, are introduced between non-crimped layers of unidirectional reinforcing fibers to produce a preform for use in liquid-molding processes to produce a composite member. Curing of the preform provides increased impact resistance by increasing the amount of energy required to propagate localized fractures due to impact.

Abstract: Water-entrained compositions comprising colloidal or suspensoidal solutions comprising polyimide pre-polymers/oligomers are described. These compositions are obtained in water by initial dispersion of the resin constituents in water to from colloids or suspensoids. The water-entrained polyimide compositions can be applied to numerous surfaces or more beneficially used for composite fabrication. The coated surfaces or polyimide-pre-polymer impregnated reinforcing materials are subsequently cured and are ideal for providing thermal protection.

Abstract: The present invention relates to a continuous, carbon fiber with nanoscale features comprising carbon and carbon nanotubes, wherein the nanotubes are substantially aligned along a longitudinal axis of the fiber. Also provided is a polyacrylonitrile (PAN) precursor including about 50% to about 99.9% by weight of a melt-spinnable PAN and about 0.01% to about 10% of carbon nanotubes. Other precursor materials such as polyphenylene sulfide, pitch and solution-spinnable PAN are also provided. The precursor can also include a fugitive polymer which is dissociable from the precursor polymer.

Abstract: Materials and methods are provided for producing preform materials for impact-resistant composite materials suitable for liquid molding. Interlayers formed of nonwoven, continuous fibers, such as spunbonded, spunlaced, or mesh fabric, are introduced between non-crimped layers of unidirectional reinforcing fibers to produce a preform for use in liquid-molding processes to produce a composite member. Curing of the preform provides increased impact resistance by increasing the amount of energy required to propagate localized fractures due to impact.

Abstract: The present invention relates to a continuous, carbon fiber with nanoscale features comprising carbon and carbon nanotubes, wherein the nanotubes are substantially aligned along a longitudinal axis of the fiber. Also provided is a polyacrylonitrile (PAN) precursor including about 50% to about 99.9% by weight of a melt-spinnable PAN and about 0.01% to about 10% of carbon nanotubes. Other precursor materials such as polyphenylene sulfide, pitch and solution-spinnable PAN are also provided. The precursor can also include a fugitive polymer which is dissociable from the precursor polymer.

Abstract: The present invention relates to a continuous, carbon fiber with nanoscale features comprising carbon and carbon nanotubes, wherein the nanotubes are substantially aligned along a longitudinal axis of the fiber. Also provided is a polyacrylonitrile (PAN) precursor including about 50% to about 99.9% by weight of a melt-spinnable PAN and about 0.01% to about 10% of carbon nanotubes. Other precursor materials such as polyphenylene sulfide, pitch and solution-spinnable PAN are also provided. The precursor can also include a fugitive polymer which is dissociable from the precursor polymer.

Abstract: A process for synthesizing formulations for polyimides suitable for use in high-temperature composites in which all reactions other than chain-extension have already taken place prior to making a composite is described, wherein the resulting oligomers comprise a backbone and at least one difunctional endcap. The resulting resin systems have only the single step of endcap-to-endcap reactions during composite processing. Prior to the initiation temperature of these endcap-to-endcap reactions, the resins are stable affording the composite manufacturer a very large processing window.