The present invention relates to a liquid crystal composite elastic fiber manufactured by means of spinning a graphene-based composition in which graphene-based materials are dispersed into a polymer solution including polymer having a polar group so that the polymer is intercalated in or chemically reacted with the graphene-based materials. The present invention also related to a method of manufacturing the same.

The present invention relates to a liquid crystal composite elastic fiber manufactured by means of spinning a graphene-based composition in which graphene-based materials are dispersed into a polymer solution including polymer having a polar group so that the polymer is intercalated in or chemically reacted with the graphene-based materials. The present invention also related to a method of manufacturing the same.

[Problem] To provide: a carbon fiber precursor fiber that can efficiently produce a carbon fiber at a low cost which is excellent in mechanical strengths even without an infusibilization treatment; a carbon fiber; and a method for producing the carbon fiber.

[Solution] A carbon fiber precursor fiber of the present invention includes a polymer containing a constituent unit represented by General Formula (1) below:

##STR00001## where in the General Formula (1), X and Y each independently represent a divalent substituent, a single bond, or a structure forming a fused ring by sharing one side of two adjacent rings, and the divalent substituent is selected from the group consisting of O, S, OSO, NH, CO, CH.sub.2, and CH(CH.sub.3).sub.2.

[Problem] To provide: a carbon fiber precursor fiber that can efficiently produce a carbon fiber at a low cost which is excellent in mechanical strengths even without an infusibilization treatment; a carbon fiber; and a method for producing the carbon fiber.

[Solution] A carbon fiber precursor fiber of the present invention includes a polymer containing a constituent unit represented by General Formula (1) below:

##STR00001## where in the General Formula (1), X and Y each independently represent a divalent substituent, a single bond, or a structure forming a fused ring by sharing one side of two adjacent rings, and the divalent substituent is selected from the group consisting of O, S, OSO, NH, CO, CH.sub.2, and CH(CH.sub.3).sub.2.

A composition for use in the formation of a lignin-based carbon fibre precursor is disclosed. The composition is a blend of a lignin and at least 10 wt % of a thermoplastic elastomer. The thermoplastic elastomer may improve the mechanical properties of the lignin-based blend to the extent that conventional carbon fibre precursor formation processes can be carried out using the blend whereas said processes would have been problematic and/or failed when using only lignin to form the carbon fibre precursors. The thermoplastic elastomer is suitably a thermoplastic polyurethane. A carbon fibre precursor produced using the composition is also disclosed, as is a carbon fibre produced from said carbon fibre precursors. Methods of forming said carbon fibre precursors and carbon fibres are also disclosed.

There is provided a method of making a hollow fiber. The method includes mixing, in a first solvent, a plurality of nanostructures, one or more first polymers, and a fugitive polymer which is dissociable from the nanostructures and the one or more first polymers, to form an inner-volume portion mixture. The method further includes mixing, in a second solvent, one or more second polymers to form an outer-volume portion mixture, and spinning the inner-volume portion mixture and the outer-volume portion mixture to form a precursor fiber. The method further includes heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and during heating, extracting the fugitive polymer from the inner-volume portion mixture. The method further includes obtaining the hollow fiber with the inner-volume portion having the nanostructures and the first polymers, and with the outer-volume portion having the second polymers.

An oil agent for a carbon fiber precursor is provided that contains a base component, a cationic surfactant, and a nonionic surfactant, wherein the cationic surfactant is a specific nitrogen-containing compound.

An oil agent for a carbon fiber precursor is provided that contains a base component, a cationic surfactant, and a nonionic surfactant, wherein the cationic surfactant is a specific nitrogen-containing compound.

The present application provides methods for producing polybenzimidazole carbon fiber that does not require infusibilization treatment.

The present application provides methods for producing polybenzimidazole carbon fiber that does not require infusibilization treatment.