Disclosed herein are copolymers formed by cationic polymerization of one or more cyclic dienes and a comonomer selected from the group consisting of a monoterpene, a branched styrene, and combinations thereof, in the presence of a catalyst. Random copolymers having repeat units derived from a cyclic conjugated diene, such as 1,3-cyclohexadiene, and a comonomer such as a monoterpene, can be prepared as soluble products in hydrocarbon solvents. The copolymers can be crosslinked with various crosslinking agents to form materials having good oxidative stability and fire retardancy. The uncrosslinked and crosslinked copolymers have useful properties such as a low dissipation factor, low dielectric constants, and a good balance of thermomechanical and electrical properties that make them valuable in electronic applications.

A conductive sheet comprising a conductive substrate layer and a hydrogel layer formed of a silicone hydrogel having a polymer comprising a repeat unit (A) derived from a monomer represented by Formula (I) as a gel skeleton. Provided is a conductive sheet which can maintain adhesiveness and flexibility even when used for a long period of time and can attain high biocompatibility.

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A conductive carbon fiber reinforced composite comprising: a metal-coated carbon fiber fabric laminated with a nanocomposite resin, the nanocomposite resin comprising a mixture of: a polymerizable thermosetting polymer, a conductive filler, and a carbonaceous fiber-like filler. A method of forming a conductive carbon fiber reinforced composite, the composite comprising a metal-coated carbon fiber fabric laminated with a nanocomposite resin, the nanocomposite resin comprising a mixture of: a polymerizable thermosetting polymer, a conductive filler, and a carbonaceous fiber-like filler, the method comprising the steps of: a) forming the nanocomposite resin; b) forming the metal-coated carbon fiber fabric; and c) laminating the metal-coated carbon fiber fabric with the nanocomposite resin using one of: a wet lay-up process followed by hot-press curing under vacuum, a vacuum infusion process, a prepreg fabrication process, and a resin transfer molding process.

The use of a sulfonated polyaryl ether ketone or of a sulfonated non-polymeric aryl ether ketone as a dispersant for a polyaryl ether ketone resin powder in an aqueous solution, and also to a corresponding composition, and to a process for preparing a semifinished product comprising a polyaryl ether ketone resin and reinforcing fibers.

A manufacturing method for a composite sheet having excellent rigidity, no shape deformation, and excellent transparency is disclosed. By laminating a film obtained by impregnating a composite resin on a wet cake including cellulose nanofibers and glycerol, rigidity and transparency may be maximized, and a flat and thick composite sheet may be provided.

An object of the present invention is to provide a carbon fiber which exhibits excellent strength development rate when used in a composite material. The present invention that solves the problems is a carbon fiber which simultaneously satisfies the following formulae (1) and (2):
Lc/d≤3  (1)
TS×d×Lc>6.0×10.sup.5  (2) wherein: Lc is an X-ray crystallite size (Å), d is a filament diameter (μm), and TS is a strand tensile strength (MPa).

An epoxy resin composition for carbon-fiber-reinforced composite material includes (A) a bisphenol F-type epoxy resin that is liquid at 25° C., (B) a polyfunctional amine-type epoxy resin, and (C) 3,3′-Diaminodiphenyl sulfone. With respect to 100 parts by mass of the entire epoxy resin in the epoxy resin composition, the content of component (A) is 40 to 60 parts by mass, the content of component (B) is 30 to 45 parts by mass, and the total content of components (A) and (B) is 85 to 100 parts by mass. The content of component (C) satisfies 1.04≤x/y≤1.35, where x is a molar number of active hydrogen atoms in the amine of component (C) and y is a molar number of all epoxy groups in the epoxy resin composition.

A glass cloth including warp yarns and weft yarns that are glass yarns each formed by bundling 30 to 44 glass filaments each having a circle-equivalent diameter of 3.0 to 4.4 μm, wherein the weaving density of the warp yarns and the weft yarns is 85 to 125 yarns/25 mm, at least either of the warp yarn and the weft yarn is a flat glass yarn formed of flat glass filaments, the weaving density thereof is less than 100 yarns/25 mm, the major axis DL of the flat glass filament is 3.3 to 6.0 μm, the minor axis DS is 2.0 to 3.9 μm, the number of twists T of each of the flat glass yarns is 0.70 twists/25 mm or less, and the number of the flat glass filaments F constituting each of the flat glass yarns, T, DL, and DS satisfy the following expression: $89.0\le F\times \left(\mathrm{DL}\times \left(1-T^{1/2}\right)+\mathrm{DS}\times T^{1/2}\right)/\left(\mathrm{DL}/\mathrm{DS}\right)\le 129.0.$

An object of the present invention is to provide a carbon fiber which exhibits excellent strength development rate when used in a composite material. The present invention that solves the problems is a carbon fiber which simultaneously satisfies the following formulae (1) and (2):
Lc/d≤3  (1)
TS×d×Lc>6.0×10.sup.5  (2) wherein: Lc is an X-ray crystallite size (Å), d is a filament diameter (μm), and TS is a strand tensile strength (MPa).

The present invention discloses the an aerogel material featuring of low thermal conductivity, low dielectric constant (low-D.sub.K) and low dielectric-loss (low-D.sub.F) and a preparation method therefor. The method comprises steps of: (1) mix and hydrolysis, (2) dispersion and condensation, (3) molding, and (4) drying. The prepared pure aerogel or fiber/aerogel composite is further processed by steps of: (5) polymer solution impregnating, (6) solvent drying and (7) crosslinking-solidifying to obtain a polymer/aerogel composite or a polymer/fiber/aerogel composite featuring of high strength, low thermal conductivity, low-D.sub.K and low-D.sub.F. The method provided by the present invention does not involve highly conductive solvents or additives, and a highly porous structure is formed so that the dielectric constant and dielectric loss of the aerogel material are significantly reduced, suitable for 5G communications, microwave circuits, protection and insulation for electric vehicle lithium battery modules.