Low cost carbon fibers from bio-renewable Lignin/Poly(lactic acid) (PLA) blends

We report that cylindrically shaped Lignin/PLA based carbon fibers having tensile strength between 258.6 and 159.2 MPa and tensile modulus ranging from 1.7 to 11.6 GPa can be prepared by melt spinning of Lignin/PLA blends followed by the thermal stabilization and carbonization of Lignin/PLA fibers. The introduction of PLA increased the spinnability of Lignin/PLA blends by employing the good spinnability of PLA, to produce continuously spooled Lignin/PLA fibers. The hydrogen-bonding interaction between lignin and PLA phases, demonstrated by DSC and FTIR, increased the tensile modulus of the blend-based carbon fibers relative to that from lignin. However, the tensile strength of Lignin/PLA based carbon fibers was decreased mainly due to the presence of voids that were caused by the volatilization of PLA in the thermal stabilization and carbonization processes.