Lignin/PLA fibers were thermally stabilized and carbonized in an
oven. The thermal stabilization process was carried out in an air
environment. Lignin/PLA fibers were heated from 60 C to 280 C at
a rate of 0.25 C/min and held for 1 h before carbonization. The
thermally stabilized fibers were subsequently carbonized in a nitrogen
atmosphere. The temperature was increased to 1000 C at a
rate of 3 C/min before cooling to room temperature.