Abstract
Chitin, distinguished by its nitrogen-rich acetamido and amino groups, imparts a distinctive cationic nature, enabling chitin with indispensable features in various applications. However, the degree of deacetylation (DD)- a key molecular-level structural determinant- has not been adequately addressed in prior studies despite its critical role in influencing chitin's properties across multiple scales. Here, by controlling the degree of acetylation, we achieved extensive tunability of the properties of regenerated chitin fibers and systematically investigated the effects of deacetylation on their structure-property relationship, relying on an aqueous KOH/urea solution green dissolution system. It is found that deacetylation is associated with the decrease of solution viscosity and the increase of solution stability, thereby improving the spinnability and augmenting the mechanical and antimicrobial qualities of fibers. Optimal overall performance is achieved with chitin exhibiting a DD of 30–40%. This work provides a deeper understanding of the structure, properties, and applications of chitin, and endows more possibilities for the production of regenerated chitin.