Molecular weight of polyvinyl acetate by light scattering and viscosity techniques

Abstract

Abstract A viscosity‐weight average molecular weight relationship was obtained for fractionated polyvinyl acetate in a thermodynamically “good” solvent acetone at 30°C. This relationship is represented by [η] = 8.6 × 10 −5 M . The value of the root‐meansquare end‐to‐end distance is approximately three times as large as the theoretical value for a chain with completely free rotation. The values of the osmotic second virial coefficient indicate the polymer molecules are expanded beyond their random flight dimensions. Consideration of the thermodynamic interactions in “good” solvent results in approximately constant values for A 2 M /[η] and A 2 M 2 /( r 2 ) 3/2 . The average value obtained for the Flory universal constant is 1.98 × 10 21 .