A new modification method of exploded lignin for the preparation of a carbon fiber precursor

A lignin‐pitch for carbon fiber was prepared in a high yield from exploded lignin on phenolysis followed by heat treatment under a vacuum. The lignin‐pitch had an excellent spinnability in the melt state to form a fine filament. The green fibers were easily made infusible when heated in air at a relatively high heating rate (15‐60°C/h). The lignin‐based carbon fiber was produced in 43.7% of yield based on a starting material. The tensile strength was more than 400 MPa, indicating that the lignin‐based carbon fiber is classified into a general purpose grade.