Improving Processing and Performance of Pure Lignin Carbon Fibers through Hardwood and Herbaceous Lignin Blends

• Published in: International journal of molecular sciences Vol. 18; no. 7; p. 1410
• Main Authors: Hosseinaei, Omid, Harper, David P, Bozell, Joseph J, Rials, Timothy G
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 01.07.2017; MDPI AG
• Subjects: Carbon - chemistry; carbon fiber; hardwood; herbaceous; lignin; Lignin - chemistry; Magnetic Resonance Spectroscopy; nuclear magnetic resonance (NMR) spectroscopy; tensile properties; Tensile Strength; thermal properties; Thermodynamics; thermostabilization; Wood - chemistry; hardwood; herbaceous; carbon fiber; tensile properties; thermal properties; lignin; nuclear magnetic resonance (NMR) spectroscopy; thermostabilization
• ISSN: 1422-0067; 1422-0067
• DOI: 10.3390/ijms18071410

Lignin/lignin blends were used to improve fiber spinning, stabilization rates, and properties of lignin-based carbon fibers. Organosolv lignin from Alamo switchgrass ( ) and yellow poplar ( ) were used as blends for making lignin-based carbon fibers. Different ratios of yellow poplar:switchgrass lignin blends were prepared (50:50, 75:25, and 85:15 ). Chemical composition and thermal properties of lignin samples were determined. Thermal properties of lignins were analyzed using thermogravimetric analysis and differential scanning calorimetry. Thermal analysis confirmed switchgrass and yellow poplar lignin form miscible blends, as a single glass transition was observed. Lignin fibers were produced via melt-spinning by twin-screw extrusion. Lignin fibers were thermostabilized at different rates and subsequently carbonized. Spinnability of switchgrass lignin markedly improved by blending with yellow poplar lignin. On the other hand, switchgrass lignin significantly improved thermostabilization performance of yellow poplar fibers, preventing fusion of fibers during fast stabilization and improving mechanical properties of fibers. These results suggest a route towards a 100% renewable carbon fiber with significant decrease in production time and improved mechanical performance.