Poly(thioctic Acid)/Phenolic-Amine Cross-Linking Multinetwork Reinforced Flexible Colored and Multifunctional Chitosan Fiber

This study proposes a strategy for preparing colored flexible chitosan fibers (PPs-TA-CS fibers) via a dual-interpenetrating multinetwork structure. By linking rigid chitosan (CS) chains to flexible thioctic acid (TA) polymers via dynamic disulfide bonds, the flexibility and mechanical properties of the fibers are significantly enhanced. Meanwhile, the incorporation of polyphenols (PPs) enables in situ coloring, eliminating the need for additional dyeing processes. The experimental results show that, compared to CS fibers, the tensile strength of the three types of PPs-TA-CS fibers increased by 97.90%, 116.25%, and 95.28%. PPs-TA-CS fibers also exhibit excellent bending flexibility and deformation capacity. Furthermore, the PPs-TA-CS fibers exhibit excellent UV-blocking and antibacterial properties. This study provides an innovative and sustainable approach for the development of high-performance, biodegradable functional fibers.