Viscosity of Maleic Anhydride-Vinyl Acetate Copolymer

摘要

The viscosities of maleic anhydride-vinyl acetate copolymer in several kinds of solventswere measured at 25℃ by the use of an Ostwald type viscometer. The reduced viscositiesin dioxane and tetrahydrofuran were proportional to the concentration， but those in polarsolvents such as acetone，N,N' / -dimethylformamide and water decreased with the increasein concentration and had minimum values at critical concentrations. lt was found that thisabnormal behavior was ascribable to an ionic structure of copolymer in polar solvent ratherthan the rate of shear and the absorption of copolymer on capillary walls.