MODIFIED LIGNIN, METHOD FOR ITS PREPARATION AND APPLICATION Russian patent published in 2023 - IPC C07G1/00 C08H7/00 

FIELD: chemical industry.

SUBSTANCE: invention relates to modified lignin based on substituted and/or unsubstituted lignin, and the lignin molecules in substituted and unsubstituted lignin (A) are connected by binding blocks (B) to increase the molecular weight. Lignin differs in that the binding blocks (B) are aromatic and are connected to lignin molecules (A) by means of a methylene group. The binding block (B) comes from the interaction of lignin (A) with an aromatic binding compound (C), which contains at least two hydroxymethyl groups. The specified modified lignin has an average calculated molecular weight from 2,000 to 50,000 g/mol. The invention also reveals a method for producing modified lignin. In addition, the invention relates to the use of modified lignin to produce fiber precursors for wet, dry-wet or dry spinning. In addition, the use of modified lignin for the production of fiber precursors by spinning from a melt is disclosed.

EFFECT: obtaining carbon fibers with valuable properties, in particular, with respect to tensile strength, as well as elastic modulus, by means of preferred fiber precursors.

24 cl, 3 dwg, 1 tbl, 8 ex