Fundamental Modeling and Experimental Investigation of Polymer Washing Process*

After polymerization reaction, impurities such as adduct, solvent and catalyst are trapped inside the polymers. These impurities should be removed by a polymer washing process to improve the purity of the polymer products. Also, the optimization of the polymer washing process is essential to reduce the energy, resources and processing time. This work provides theoretical basis for optimization of polymer washing process by proposing a fundamental model and experimental investigation method of the process. The model describes the impurity distribution inside the polymers, mole balance of impurities inside and outside of the polymers, and impurity diffusion rate at polymer surface. The experimental investigation with SPAEK (sulfonated poly(aryl ether ketone)) samples reports the impurity diffusion coefficient at polymer surface of the performed experiments. The computed D(the impurity diffusion coefficient at the polymer surface) shows different values with time as a lumped parameter, including the unmodelled effects for impurity diffusion. However, these values show the same trajectory with the introduction of a dimensionless number Co for each operation. This means unmodelled impurity diffusion factors included in D are only affected by Co. Finally, we validate the prediction performance of the model by comparing the predicted pH changes of validation experiment with the experimental data.