Disassociated molecular orientation distributions of a composite cellulose–lignin carbon fiber precursor: A study by rotor synchronized NMR spectroscopy and X-ray scattering

• Published in: Carbohydrate polymers Vol. 254; p. 117293
• Main Authors: Svenningsson, Leo, Bengtsson, Jenny, Jedvert, Kerstin, Schlemmer, Werner, Theliander, Hans, Evenäs, Lars
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.02.2021
• Subjects: Associated costs; Automobile manufacturing; Carbon Fiber - chemistry; Carbon fiber precursors; Carbon fibers; Cellulose; Cellulose - chemistry; Composite; Cost reduction; Creep resistance; Environmentally benign; Fiber; Fibers; Graphite fibers; Lightweight materials; Lignin; Lignin - chemistry; Magnetic Resonance Spectroscopy - methods; Molecular orientation; Molecular orientation distribution; Molecular Structure; Nuclear magnetic resonance spectroscopy; Orientation distributions; Picea - chemistry; Polyacrylonitrile precursors; Regenerated cellulose; Rotor synchronized magic-angle spinning; Solid state nuclear magnetic resonance spectroscopy; Solid-state NMR; Solubility; Tensile Strength; Viscosity; Wind power; Wood; Wood - chemistry; X ray scattering; X-Ray Diffraction - methods; Lignin; Solid-state NMR; Carbon fibers; X-ray scattering; Wood; Composite; Regenerated cellulose; Fiber; Rotor synchronized magic-angle spinning; Molecular orientation distribution
• ISSN: 0144-8617; 1879-1344; 1879-1344
• DOI: 10.1016/j.carbpol.2020.117293

[Display omitted] •ROSMAS solid-state NMR is s reliable technique to differentiate molecular species and their orientations in a material.•Solid-state NMR reveals the cellulose and lignin orientation in composite fibers and native wood.•A combination of solid-state NMR and X-ray scattering provides complimentary information to determine the orientation distribution function. Cellulose–lignin composite carbon fibers have shown to be a potential environmentally benign alternative to the traditional polyacrylonitrile precursor. With the associated cost reduction, cellulose–lignin carbon fibers are an attractive light-weight material for, e.g. wind power and automobile manufacturing. The carbon fiber tenacity, tensile modulus and creep resistance is in part determined by the carbon content and the molecular orientation distribution of the precursor. This work disassociates the molecular orientation of different components in cellulose–lignin composite fibers using rotor-synchronized solid-state nuclear magnetic resonance spectroscopy and X-ray scattering. Our results show that lignin is completely disordered, in a mechanically stretched cellulose–lignin composite fiber, while the cellulose is ordered. In contrast, the native spruce wood raw material displays both oriented lignin and cellulose. The current processes for fabricating a cellulose–lignin composite fiber cannot regain the oriented lignin as observed from the native wood.