Properties of cellulose acetate in solution. I. Light scattering, osmometry, and viscometry on dilute solutions

Light‐scattering, osmotic pressure, and viscometric studies on fractions of cellulose acetate (degree of substitution 2.45) in three solvents are described. The data yield the dependence of the mean‐square radius of gyration 〈 s 2 〉, the second virial coefficient Γ 2 , and the intrinsic viscosity [η] on molecular weight M and temperature. The results are interpreted to show that excluded volume effects on 〈 s 2 〉 are negligible, even though Γ 2 is large and d Γ 2 / dT is positive. The large experimental value of d In [η]/ d In M is interpreted in terms of partial draining effects. Data on 〈 s 2 〉 and [η] for other cellulose esters in the literature are similarly interpreted. Significant aggregation found in solutions of cellulose acetate in many solvents is discussed.