Study on the coagulation process of cellulose nascent fibers with ionic liquid AMIMCl as a solvent during dry-wet spinning

The coagulation process of nascent fiber of cellulose with ionic liquid 1-allyl-3-methylimidazolium chloride (AMIMCI) as the solvent was studied during dry-wet spinning. The diffusion rate and the crystallization situation of nascent fiber were tested, its fracture morphology was observed, and the diffusion coefficient D of solvent and the crystallization degree of nascent fiber were calculated according to relevant equations. The diffusion rate and diffusion coefficient of ionic liquid decrease with cellulose concentration increasing in spinning solution and then remain almost the same when the cellulose mass fraction reaches 7%. With the increase of coagulation bath concentration, the diffusion rate and diffusion coefficient of the solvents increase first and then decrease. When the coagulation bath concentration reaches 5%, the diffusion rate and diffusion coefficient of the solvents are at their maximum. With the increase of coagulation bath temperature and the length of air gap, the diffusion rate and diffusion coefficient of ionic liquid increase slightly. The cellulose solution concentration and the spinning air gap have an influence on the crystallization degree of nascent fiber. With the increase of cellulose solution concentration and the spinning air gap, the crystallization degree of the produced nascent fiber increases slightly, but the coagulation bath temperature basically have no influence on the nascent fiber formation.