Continuous Pilot‐Scale Wet‐Spinning of Biocompatible Chitin/Chitosan Multifilaments from an Aqueous KOH/Urea Solution

Abstract Chitin is a promising natural polymer with great potential as a biomedical, hygiene, absorbent, and food‐packing material. Producing chitin multifilament and assembling them into textiles is an efficient way of preparing these materials, with wet‐spinning a major method used to produce man‐made fibers. Unfortunately, dissolving chitin, producing a stable and suitable chitin dope, and ensuring filament strength are the main obstacles to the production of chitin multifilament. Based on recent research into chitin dissolution, solution properties, and high‐strength chitin‐based materials, chitin multifilament wet‐spinning is no longer only a hypothetical strategy. Here, a pilot‐scale wet‐spinning method is introduced that overcomes the abovementioned limitations. A stable chitin spinning dope is prepared by dissolution and aging in an aqueous KOH/urea solution. A chitin multifilament is prepared by wet‐spinning using a pilot‐scale wet‐spinning apparatus and aqueous alcohol/salt coagulation. After deacetylation, the chitosan multifilament possesses a dense structure and low crystallinity, but excellent mechanical properties. The chitin/chitosan multifilaments exhibit excellent cytocompatibilities and have promising prospects in biomedical applications. The method developed in this work provides a new approach for the pilot‐scale wet‐spinning of chitin/chitosan multifilaments.