Preparation of strong and tough alginate fibers through multiple Ca2+ crosslinking structures and interpenetrating networks

Green and low carbon development has become an unstoppable mainstream of the global and forced a trend of developing biomass fibers with high performance. Alginate fiber is an important component of marine biobased fibers that has gained widespread interest recently. However, applications of alginate fiber are facing challenges because of its limited mechanical properties. Here, we developed a novel design to prepare structurally enhanced alginate fibers alginate fiber by constructing multiple Ca 2+ crosslinked and interpenetrating networks in alginate chains. Through the synergistic effect of two biocompatible polymers, the entanglement of alginate chains was improved and the viscosity was controlled at a certain level which would not affect the fiber forming. The as-spun alginate fibers without further stretching possess a breaking strength of 265.7 MPa, elongation at break of 19.6 %, outperforming most alginate fibers enhanced by adding reinforcement additives. Improving the intermolecular entanglement to enhance the mechanical properties paves a new way for fabricating high-performance alginate fibers.