Carbon fibers based on pyrolytic lignin

Carbon fibers were prepared from pyrolytic lignin isolated from a commercial bio‐oil by thermal spinning followed by carbonization. Compared to other technical lignins, a lower spinning temperature was required for the pyrolytic lignin. The pyrolytic lignins tended to develop fibers with hollow structures and were observed to fuse together during thermostabilization. However, a thermal treatment before fiber spinning was found to maintain the fiber integrity during thermostabilization and the following carbonization process. The mechanical properties and yield of the pyrolytic‐lignin‐based carbon fiber was found to be comparable to those based on other technical lignins. This work serves as a proof‐of‐concept study indicating pyrolytic lignin as a potential feedstock for low‐cost carbon‐fiber production.