The present application relates to a sizing agent composition, a carbon fiber material and a composite material. The sizing agent composition comprises specific compositions, thereby producing a sizing agent having emulsion droplets with specific diameter. The sizing agent has excellent emulsion stability, and it can efficiently improve hygroscopicity and dimensional stability of the carbon fiber material. Besides, the sizing agent can improve bonding properties between the carbon fiber material and resin matrix, therefore enhancing properties of the composite material.

A process for preparing surface-modified carbon, comprising adding carbon material to a solution of a reaction product of primary aromatic amine and excess molar amount of nitrite source, and recovering surface-modified carbon bearing redox-active sites. Surface-modified carbon material, electrodes and capacitors based thereon are also provided.

A vanillin is found to be a useful starting material for preparing new monomers that can be further applied to make high Tg composite resins that are in turn useful for making composite parts.

A vanillin is found to be a useful starting material for preparing new monomers that can be further applied to make high Tg composite resins that are in turn useful for making composite parts.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state.

All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state. All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state.

All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state. All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

The present application relates to a sizing agent composition, a carbon fiber material and a composite material. The sizing agent composition comprises specific compositions, thereby producing a sizing agent having emulsion droplets with specific diameter. The sizing agent has excellent emulsion stability, and it can efficiently improve hygroscopicity and dimensional stability of the carbon fiber material. Besides, the sizing agent can improve bonding properties between the carbon fiber material and resin matrix, therefore enhancing properties of the composite material.

A method for converting vanillin to bis(cyanate) ester monomers, comprising treating vanillin with a reductive coupling agent to form at least one olefin. The olefin or olefins are treated with hydrogen and a metal catalyst to hydrogenate said olefin. The hydrogenated olefin or olefins are treated with at least one cyanogen halide and a base in an organic solvent to afford at least one olefin monomer. The olefin monomer or monomers are purified by recrystallization or precipitation from an organic solvent.