Close Packing of Cellulose and Chitosan in Regenerated Cellulose Fibers Improves Carbon Yield and Structural Properties of Respective Carbon Fibers

Abstract

A low carbon yield is a major limitation for the use of cellulose-based filaments as carbon fiber precursors. The present study aims to investigate the use of an abundant biopolymer chitosan as a natural charring agent particularly on enhancing the carbon yield of the cellulose-derived carbon fiber. The ionic liquid 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH]OAc) was used for direct dissolution of cellulose and chitosan and to spin cellulose–chitosan composite fibers through a dry-jet wet spinning process (Ioncell). The homogenous distribution and tight packing of cellulose and chitosan revealed by X-ray scattering experiments enable a synergistic interaction between the two polymers during the pyrolysis reaction, resulting in a substantial increase of the carbon yield and preservation of mechanical properties of cellulose fiber compared to other cobiopolymers such as lignin and xylan.

Fast and quantitative compositional analysis of hybrid cellulose-based regenerated fibers using thermogravimetric analysis and chemometrics

“…Cellulose pulp, mixtures of cellulose-lignin and cellulose-chitosan, with controlled mass proportions, were dissolved in [DBNH][OAc] inside a high shear kneader (80°C, 90 min, 7 ± 3 mbar, mixing 30 rpm). The IL-biopolymers solutions were then filtered in a filter press unit (5 lm metal mesh pore size) and dryjet wet spun using a piston spinning unit (Fourné Polymertechnik, Germany), as described in our previous articles (Zahra et al 2020;Trogen et al 2021). The spun fiber codes, their corresponding cellulose share and total biopolymers concentration during dissolution are summarized in Table 1.…”

“…The spun fiber codes, their corresponding cellulose share and total biopolymers concentration during dissolution are summarized in Table 1. No 100% lignin or chitosan solutions could be spun into fibers because such solutions do not have the adequate viscoelastic properties needed for this particular ILbased dry-jet wet spinning (Zahra et al 2020;Trogen et al 2021).…”

“…Using the Ioncell Ò technology (Sixta et al 2015), we are able to dissolve mixtures of biopolymers in a protic ionic liquid and spin the solution into hybrid fibers. The obtained hybrid fibers are composed of two or more biopolymers forming nanoscale mixtures inside a micrometric fibrous matrix (Mikkilä et al 2020;Zahra et al 2020;Le et al 2020;Trogen et al 2021).…”

“…Hybrid fibers like cellulose-lignin (Bengtsson et al 2019;Mikkilä et al 2020;Le et al 2020;Trogen et al 2021), cellulose-chitosan (Zahra et al 2020), cellulose-chitin (Ota et al 2020) or cellulose-betulin (Makarov et al 2018) have found applications in textiles (Ma et al 2015) or as precursors for biobased carbon fibers (Byrne et al 2016). The presence of a second biopolymer provides to the hybrid fiber new functional properties that can be fine-tuned by controlling the share of the biopolymer in the fiber.…”

Facile preparation and performance study of antibacterial regenerated cellulose carbamate fiber based on N-halamine

“…Regenerated cellulose fibers, including cellulose carbamate fibers, lacking antibacterial properties has restricted their development and application in medical and health-related fields (Elsayed et al 2020 ; Fu et al 2014b ; Zahra et al 2020 ). In particular, with the outbreak of coronavirus disease (COVID-19) which caused incalculable disasters and economic losses, the antibacterial properties of regenerated fibers have received increasing attention (Desai and Aronoff 2020 ; He et al 2020 ).…”