Fibers based on cellulose-chitin blends

Fibers made of cellulose (CE) and chitin (CH) in different proportion were wet spun from solutions in dimethylacetamide containing 5% LiCl (w/w). Polymer concentration was purposely maintained as low as possible (2.4% w/w). Moreover, dope temperature was 60°C to have good spinability. Comparison of the elastic modulus (E) of fibers as spun at different CE/CH ratio showed a synergy between the components: at CE/CH 50/50, E is 15 GPa with respect to 9 and 11 GPa for neat CE and CH fibers, respectively. Application of a pull-off ratio during the coagulation allows the E value to increase further. These results, as well as the electronic microscopy of fibers section, agree with a complete miscibility of two polymers at the solid state, probably enhanced by the presence of LiCl.