Ionic liquids offer alternative methods for the sustainable processing of natural biopolymers like chitosan. The ionic liquid 1-butyl-3-methylimidazolium acetate (BmimOAc) was successfully used for manufacturing of pure chitosan-based monofilaments by a wet spinning process at lab-scale. Commercial chitosan with 90% deacetylation degree was used for the preparation of spinning dopes with solids content of 4–8 wt.%. Rheology tests were carried out for the characterization of the viscometric properties. BmimOAc was used as a solvent and deionized water as coagulation and washing medium. Optical (scanning electron microscope (SEM), light microscope) and textile physical tests were used for the evaluation of the morphological and mechanical characteristics. The manufactured chitosan monofilaments a homogeneous structure with a diameter of ~150 μm and ~30 tex yarn count. The mechanical tests show tensile strengths of 8 cN/tex at Young’s modulus up to 4.5 GPa. This work represents a principal study for the manufacturing of pure chitosan fibers from ionic liquids and provides basic knowledge for the development of a wet spinning process.

While carbon fibers (CFs) are still the most attractive reinforcement material for lightweight structures, they are mostly manufactured using crude oil-based process chains. To achieve a higher eco-efficiency, the partial substitution of polyacrylonitrile (PAN) by renewable materials, such as lignin, is investigated. So far, this investigation has only been carried out for batch manufacturing studies, neglecting the transfer and validation to continuous CF manufacturing. Therefore, this work is the first to investigate the possibility of partial substituting lignin for PAN in a continuous process. Lignin/PAN-blended CFs with up to 15 wt.-% lignin were able to attain mechanical properties comparable to unmodified PAN-based carbon fibers, achieving tensile strengths of up to 2466 MPa and a Young’s Modulus of 200 Pa. In summary, this study provides the basis for continuous Lignin/PAN-blended CF manufacturing.

The ionic liquid 1‐ethyl‐3‐methyl‐imidazolium acetate (EMIMOAc) is used to develop a wet‐spinning process for the manufacturing of chitosan multifilament yarns on a semi‐industrial pilot scale. Commercial chitosans of different qualities, properties, and deacetylation degree ≤85% are used to prepare of spinning dopes with solids content of 6.0–8.5 wt.% using EMIMOAc as a solvent. The viscometric properties are characterized by rheological tests. The manufacturing of the pure chitosan multifilament yarns of different fineness and filament count from the prepared spinning dopes is performed on a pilot wet‐spinning plant. The obtained yarn properties are evaluated by optical (scanning electron microscope, light microscope), structural (infrared spectroscopy, X‐ray diffraction), and textile‐physical characterization. Chitosan multifilament yarns with high performance, tenacities of ~20–26 cN tex⁻¹ and textile processability in weaving, knitting and braiding processes are manufactured in this work.

E-mobility systems require the provision of efficient, lightweight and durable battery solutions. Here, novel solutions for efficient energy storage are needed, which aim at combining the performance of supercapacitors with structural capabilities realized by the use of functional carbon fibers. To achieve functional carbon fibers, different additives are used to modify carbon fibers starting with the precursor. Polyacrylonitrile blends with nanocellulose, graphene or polycyclic aromatic hydrocarbon have been spun using solvent wet spinning. Different ratios of post-drawing were performed to investigate the influence on the mechanical properties of the precursor fibers. They were characterized by tensile tests and morphological investigations.

Chitosan fibers (CHS) are a promising bio‐based precursor for carbon materials. However, their stabilization behavior and early‐stage thermal conversion are not well understood in fiber form. This study systematically investigated the thermo‐oxidative stabilization of chitosan yarns using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier‐transform infrared spectroscopy (FTIR) in air and nitrogen atmospheres. Stepwise stabilization experiments revealed that major chemical transformations, including dehydration, cleavage of CO/COC linkages, and changes in C–H functionalities, were largely complete within 15 min at the investigated temperatures. Extended dwell times confirmed reaction completion and revealed minor residual endothermic processes at higher temperatures. FTIR analysis showed that stabilization primarily alters functional group chemistry while leaving the overall nitrogen content largely unaffected. Carbonization experiments conducted to evaluate carbon yield showed that stabilized fibers exhibited carbon yields comparable to or slightly lower than those obtained by direct carbonization. These results provide insight into the stabilization behavior of CHS and clarify the roles of atmosphere and dwell time during early thermal conversion. This contributes to our understanding of fiber‐based chitosan precursors for developing carbon materials.

Chitin-based filament yarns have great potential for use in biomedical and technical textiles. However, their processing and applicability are severely limited by poor solubility and inefficient solvent removal, restricting scalable manufacturing. This study investigates the development and scale-up of a wet spinning process for chitin yarns using the ionic liquid 1-ethyl-3-methylimidazolium propionate (EMIMOPr). Solvent removal during monofilament spinning was investigated using Fourier-transform infrared spectroscopy and thermogravimetric analysis to examine its dependence on filament diameter, coagulation temperature, and residence time. The results demonstrated that solvent removal is governed by mass transport processes, with residual solvent potentially persisting in the filament core under laboratory-scale conditions. Based on these insights, multifilament spinning on a pilot scale was successfully implemented, enabling efficient solvent removal during coagulation and washing stages. The resulting yarns exhibited homogeneous morphology and consistent textile-mechanical properties. This process provides a promising platform for the large-scale production of chitin filament yarns for advanced biomedical and technical applications.