VISCOSITY OF POLYVINYL ACETATE) AND ITS CONCENTRATED-SOLUTIONS

In the reported theoretical study, 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 multiplied by 10**3 less than M less than 1. 3 multiplied by 10**6, the range 0. 15 less than phi less than 1. 0 of the volume fraction phi of polymer, the temperature range 308 to 430 degree K for PVOAc and its solutions in DEP, and at 396 degree K in CeOH. The latter is the THETA temperature for dilute solutions of PVOAc in CeOH. The data are analyzed with the relation eta equals KX//c alpha **2// phi phi M/M//c) **a exp left bracket 1/ beta (T minus T//0) right bracket , where a is 1 or 3. 4 for alpha **2// phi phi M less than or greater than a constant M//c, respectively, and X//C is a constant. The expansion factor alpha // phi of the chain dimension is found to be essentially unity for phi greater than ca. 0. 25, increasing with decreasing phi for smaller phi . Both beta and T//0 depend on phi , and T//0 also depends on M at low M.