Phase Separation of Cellulose Derivatives: Effects of Polymer Viscosity and Dielectric Constant of Nonsolvent

In systems containing either cellulose acetate butyrate or ethylcellulose, the intrinsic viscosity of the polymer in the appropriate solvent had no effect on the phase type separated. The latter was dependent on the dielectric constant of the nonsolvent added. Nonsolvents possessing relatively high dielectric constants produced a flocculate phase, while either a coacervate or gel was formed after the addition of nonsolvents of lower dielectric constant.