Embodiments of the present invention include composite compositions extrusion compounded together comprising a polymer, an amount of nanotubes, and an amount of finely milled carbon fiber having an aspect ratio greater than 1 and less than about 5. The resulting composite materials allow for high carbon loading levels with improved tribological properties including coefficient of friction and wear rates, provides uniform surface resistance with minimal processing sensitivity, retains rheological properties similar to the base resin, and provides isotropic shrink and a reduced coefficient of thermal expansion leading to minimal warp. In general, various articles can be formed that take advantage of the properties of the composite materials incorporating a polymer, carbon nanotubes and finely milled carbon fiber.

Provided is a prepreg including: a fiber layer containing unidirectionally arranged carbon fibers impregnated with a first thermosetting resin; and a resin layer disposed on at least one side of the fiber layer and containing a second thermosetting resin and a thermoplastic resin that is insoluble in the second thermosetting resin. The prepreg is configured such that the areal weight of fibers and the weight fraction of resin in the prepreg are 120 to 300 g/m.sup.2 and 25 to 50 mass %, respectively, and in the case where a plurality of prepregs are laid up, and the coefficient of interlayer friction is measured every 10° C. in a temperature range of 40 to 100° C. at a pull-out speed of 0.2 mm/min under a perpendicular stress of 0.8 bar, the temperature at which the coefficient of interlayer friction is 0.02 or less is present within a temperature range of 40 to 100° C. The prepreg exhibits high impact strength when formed into a fiber-reinforced plastic suitable for an aircraft structural member, and the prepreg also has excellent drapeability when a prepreg laminate is made to conform to a three dimensional shape.

Disclosed are a reinforcing fiber bundle composed of a carbon fiber bundle treated with an emulsion; a carbon fiber reinforced thermoplastic resin molded body using the same; and a method for producing a reinforcing fiber bundle; wherein the emulsion contains a modified polyolefin (A1) comprising at least a metal carboxylate bonded to the polymer chain, and 0.1 to 5,000 moles of an amine compound (B) represented by the following general formula (1), per one mole of the carboxylate group in the modified polyolefin (A1);

R—NH.sub.2  (1) wherein the formula (1), R is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

A carbon-fiber-reinforced resin composite material includes: carbon fibers including carbon fiber bundles and a thermoplastic resin, in which (1) a coefficient of variation (CV1) of a total areal weight of the carbon-fiber-reinforced resin composite material is 10% or lower, (2) a coefficient of variation (CV2) of a carbon fiber volume fraction (Vf) in the carbon-fiber-reinforced resin composite material which is defined by Expression (a) is 15% or lower, and (3) a weight average fiber length of the carbon fibers is 1 to 100 mm. Carbon Fiber Volume Fraction (Vf)=100×Volume of Carbon Fibers/(Volume of Carbon Fibers+Volume of Thermoplastic Resin) . . . Expression (a).

The present disclosure generally relates to systems and methods for composites, including short-fiber films and other composites. In certain aspects, composites comprising a plurality of aligned fibers are provided. The fibers may be substantially aligned, and may be present at relatively high densities within the composite. For example, the composite may include substantially aligned carbon fibers embedded within a thermoplastic substrate. The composites may be prepared, in some aspects, by dispersing fibers by neutralizing the electrostatic interactions between the fibers, for example using aqueous liquids containing the fibers that are able to neutralize the electrostatic interactions that typically occur between the fibers. The liquids may be applied to a substrate, and the fibers may be aligned using techniques such as shear flow and/or magnetism. Other aspects are generally directed to methods of using such composites, kits including such composites, or the like.

The present invention relates to resin compositions, fiber reinforced polymeric structures and electromagnetic induction processes for making same. Such magnetic induction processes are pulsed processes that can be optionally coupled with cooling steps between pulses. The aforementioned fiber reinforced polymeric structures can take forms that include, but are not limited to, pipes; pressure vessels, including rocket motor cases and fire extinguishers; golf club shafts; tennis and badminton racquets; skis; snowboards; hockey sticks; fishing rods; bicycle frames; boat masts; oars; paddles; baseball bats; and softball bats. In addition, such fiber reinforced polymeric structures can be supplemented with other materials, such as a rocket propellant, to form articles, for example, a rocket motor.

Disclosed herein is an electrically conductive sized fiber including a fiber and a sizing composition adhered to a surface of the fiber, wherein the sizing composition includes at least one sizing compound and a plurality of graphene oxide nanoparticles, The present disclosure also discloses fiber-reinforced resin composites, articles including fiber-reinforced resin composites and methods of making such electrically conductive sized fiber and articles therefrom.

A fiber-reinforced thermoplastic resin filament is obtained by impregnating a continuous reinforcing fiber with a thermoplastic resin, and satisfies all of conditions (a) to (c). (a) The volume ratio of a reinforcing fiber in a fiber-reinforced thermoplastic resin filament is 30 to 80%; and the volume ratio of a thermoplastic resin in a fiber-reinforced thermoplastic resin filament is 70 to 20%. (b) The thickness of a fiber-reinforced thermoplastic resin filament is 0.01 to 3 mm. (c) The length of a filament contained in a fiber-reinforced thermoplastic resin filament is 1 m or more.

A laminate body is provided which contains a thin prepreg having a component (A) containing a matrix of reinforcing fiber, a component (B) containing a thermosetting resin, and a component (C) containing particles of a thermoplastic resin. When molded and cured out of autoclave, the laminate body achieves a fiber-reinforced composite having a low void ratio and providing excellent mechanical performance.

A fiber-reinforced resin composite sheet of the present invention contains: a polyamide resin film containing a dicarboxylic acid component (a) and a diamine component (b); and a plurality of reinforcing fibers laminated in a state of being oriented in the same direction on the polyamide resin film, the reinforcing fibers being obtained by opening a reinforcing fiber bundle. The dicarboxylic acid component (a) contains 60 mol % or more and 100 mol % or less of terephthalic acid. The diamine component (b) contains 60 mol % or more and 100 mol % or less of 1,9-nonanediamine and 2-methyl-1,8 octanediamine. The fiber-reinforced resin composite sheet has a volume content rate Vf of the reinforcing fibers of 20% or more and 70% or less and a thickness of 20 μm or more and 70 μm or less.