▎ 摘　　要

NOVELTY - Low-molecular-weight lignin derivative comprises phenyl-based repeating unit (I). USE - The low-molecular-weight lignin derivative is useful for producing carbon fiber, activated carbon, biochar, artificial graphite and graphene material containing anode material and electrical conductive layer, and hybrid silicon carbide (all claimed). ADVANTAGE - The low-molecular-weight lignin derivative can reduce energy consumed in the carbonization process by using low molecular weight lignin into which functional groups are introduced, has biocompatibility by using biomaterials, excellent low-temperature processability due to the low glass transition temperature, and is easily purified due to the non-crystallinity of the functional group. DETAILED DESCRIPTION - Low-molecular-weight lignin derivative comprises phenyl-based repeating unit of formula (I). Ar1 and Ar2=4-14C aryl or 4-14C heteroaryl (both are optionally substituted by halo, 1-3C alkyl 1-3C alkenyl, 1-3C alkynyl, 1-3C alkoxy, glycidyl, SH, NH2, NO2, (C)N, C(O)Ra1, OC(O)Ra1, C(O)ORa1, C(O)NHRa1, SiH Ra, SOH, PO H or 5-10C heteroaryl); Ra1=H, 1-3C alkyl, or 1-3C alkenyl; and A1 and A2=H or OCH . An INDEPENDENT CLAIM is also included for producing low-molecular-weight lignin derivatives, comprising (a) mixing and reacting lignin, a monomolecular aromatic compound, and an acid catalyst, and (b) dissolving the mixture prepared by the reaction in step (a) in an organic solvent and purifying; #carbon fiber produced by using the low-molecular-weight lignin derivative.