HYDRODYNAMIC AND MOLECULAR CHARACTERISTIC S OF WATER-SOLUBLE METHYLCELLULOSE

Hydrodynamic characteristics of methylcellulose with an average degree of substitution 1.68 were studied in dilute aqueous solutions. In the range of molecular masses extending from 1 x 10(4) to 4.08 x 10(5), s edimentation coefficients, diffusion coefficients, and intrinsic visco sity were found to be related to the molecular mass by the following r elationships (25 degrees C): S = 2.21 x 10(-15) M(0.39) s, D-0 = 1.91 x 10(-4) M(-0.61) cm(2)/s, [eta] = 2.08 x 10(-2) M(0.83) cm(3)/g. On t he basis of theories describing the hydrodynamic behavior of chain mol ecules in the absence of steric effects, equilibrium rigidity and hydr odynamic diameter of methylcellulose molecules were evaluated. The res ults obtained are compared with the data reported for other water-solu ble polysaccharides.