MODELING AND SIMULATION OF THE COAGULATION PROCESS OF POLY(ACRYLONITRILE) WET-SPINNING

The coagulation process of PAN (poly(acrylonitrile)) wet-spinning was modeled and simulated based on the numerical analysis of the coagulati on of a viscous polymer solution by diffusional interchange with a bat h. Experiments were performed with gelled solutions of PAN in nitric a cid to determine the diffusion rate of solvent and nonsolvent (water) during the coagulation. The experimental data were analyzed by using e quations of diffusion coefficient which are a function of the solvent concentrations of the coagulation bath and the filament. The concentra tion profile of solvent in moving filament was predicted by solving th e diffusion model equation numerically. A simplex method was used in t he computation of the parameters of the diffusion equations to minimiz e the difference between the numerical results and experimental data.