Fungal-Derived Biobased Filaments for Textile Applications: Effect of Plasticizer and Cross-Linking Agent

Abstract Fungal cell wall polymers derived from food waste have recently emerged as a renewable platform for novel biobased fibers. In this study, fungal biomass of Rhizopus delemar cultivated on bread waste was processed to isolate the alkali-insoluble cell wall material rich in chitin and chitosan, which was converted into a hydrogel spinning dope for dry gel spinning of continuous filaments. A molecular design strategy was employed to tailor filament performance using vanillin as a biobased cross-linker and glycerol as a plasticizer. The impact of these modifications on the properties of the filaments was systematically evaluated. Vanillin provided only marginal improvement in tenacity, suggesting that its incorporation did not substantially reinforce the chitosan-rich network. In contrast, glycerol incorporation significantly enhanced filament ductility and reduced brittleness during postspinning deformation processes such as twisting, thereby enabling stable yarn formation, although with a reduction in tensile strength. Multifilament yarns were successfully fabricated, and knitted textile specimens were produced for the first time from fungal-derived yarns, demonstrating structural integrity under textile processing conditions. This study establishes a structure–property framework for balancing stiffness and flexibility in fungal-based filaments and advances their development toward engineered, renewable textile materials.