Production of carbon fiber used as e.g. lightweight automobile component, involves spinning precursor fiber filament from solution comprising nanocellulose fibril, and carbonizing filament by pyrolysis at elevated temperature

NOVELTY - Production of carbon fiber (1004) involves spinning precursor fiber filament from solution or dispersion comprising nanocellulose fibrils with a mean diameter less than 50 nm, and carbonizing (1002) the filament by pyrolysis at an elevated temperature. USE - Production of carbon fiber (claimed) used as lightweight, fuel efficient automobile and aircraft components. ADVANTAGE - The method produces carbon fiber having improved melt spinnability and processability, high aromatic content and improved crosslinking property, due to the addition of lignin. DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart of production of carbon fibers. Mixing process (110) Stabilization step (1001) Carbonization process (1002) Graphitization process (1003) Carbon fibers (1004) Technology Focus/Extension Abstract: TECHNOLOGY FOCUS - TEXTILES AND PAPER - Preferred Properties: The mean diameter of the group (I) of fibrillar nanostructures is greater than the mean diameter of the nanocellulose fibrils and the mean diameter of the group (II) of fibrillar nanostructures is less than or equal to the mean diameter of the nanocellulose fibrils. The nanocellulose fibrils have a mean diameter of less than 40 nm, preferably less than 5 nm. The cellulose precursor comprises nanofibrils having a mean diameter less than 50 nm and the carbon fibers have elongated nanostructures with a mean diameter of 5-200 nm and a mean length of 5-20 mu m. Preferred Composition: The precursor fiber filament further comprises lignin. The solution or the dispersion comprises an organic solvent. The precursor fiber filament is a composite fiber comprising nanocellulose fibril and a polymer which is at least partially soluble in organic solvent. The halogen content in the halogenated nanocellulose fibrils is 2-50 wt.%. The nanocellulose fibril is derived from higher order plants and from Spinifex grass. The higher order plant comprises lignin and hemicellulose. An additive chosen from catalyst is further added during the process