High‐Strength Composite Fibers from Cellulose–Lignin Blends Regenerated from Ionic Liquid Solution

Abstract

Composite fibres that contain cellulose and lignin were produced from ionic liquid solutions by dry-jet wet spinning. Eucalyptus dissolving pulp and organosolv/kraft lignin blends in different ratios were dissolved in the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-enium acetate to prepare a spinning dope from which composite fibres were spun successfully. The composite fibres had a high strength with slightly decreasing values for fibres with an increasing share of lignin, which is because of the reduction in crystallinity. The total orientation of composite fibres and SEM images show morphological changes caused by the presence of lignin. The hydrophobic contribution of lignin reduced the vapour adsorption in the fibre. Thermogravimetric analysis curves of the composite fibres reveal the positive effect of the lignin on the carbonisation yield. Finally, the composite fibre was found to be a potential raw material for textile manufacturing and as a precursor for carbon fibre production.

Enhanced stabilization of cellulose-lignin hybrid filaments for carbon fiber production

“…Filaments with 20 wt.% lignin (relative to cellulose) were spun from a solution with 15 wt.% polymer concentration, 40 wt.% lignin fibers from 18 wt.% polymer solution, respectively. Details regarding the synthesis of the ionic liquid, solution preparation and spinning equipment have been described previously (Ma et al 2015). The composition of the fibres used in this study with their sample codes are summarized in Table 1.…”

“…The addition of lignin lowers the T d and increases the mass yield. This is expected since lignin is a high carbon content polymer and typically has a lower thermal degradation temperature as compared to cellulose (Ma et al 2015). The addition of lignin increases the activation energy slightly.…”

“…It was found, that the same solvent, 1,5-diazabicyclo[4.3.0]non-5-ene-1-ium acetate ([DBNH]OAc), is also capable of dissolving lignin of various origin (Ma et al 2015). This opened up an entirely new approach to the utilization of lignin.…”

“…Thus, a very broad set of lignin types can be used. It was possible to spin fibres with up to 50 wt.% lignin (Ma et al 2015).…”

Targeted pre-treatment of hemp bast fibres for optimal performance in biocomposite materials: A review

“…Studies are emerging on how to produce continuous form of filaments (also called regenerated fibres) using ionic liquids as dissolution solvent (Ma et al 2015;Michud et al 2015). Ionic liquids (ILs) have some unique, advantageous properties such as low toxicity, low evaporation and high thermal stability.…”