Viscosity of poly(vinyl acetate) and its concentrated solutions

Abstract

Abstract Data on the viscosity of poly(vinyl acetate) (PVOAc) and its concentrated solutions in diethyl phthalate (DEP) and cetyl alcohol (CeOH) are examined over the molecular weight range 8 × 10 3 < M < 1.3 × 10 6 , the range 0.15 < φ < 1.0 of the volume fraction φ of polymer, the temperature range 308 to 430°K for PVOAc and its solutions in DEP, and at 396°K in CeOH. The latter is the θ temperature for dilute solutions of PVOAc in CeOH. The data are analyzed with the relation η = KX c (α φ M / M c ) a exp[1/β( T – T 0 )], where a is 1 or 3.4 for α φ M less than or greater than a constant M c , respectively, and X C , is a constant. The expansion factor α φ of the chain dimension is found to be essentially unity for φ > ca. 0.25, increasing with decreasing φ for smaller φ. Both β and T 0 depend on φ, and T 0 also depends on M at low M .