dilute solutions

The viscometric properties of diluted solutions of cellulose diacetate in dimethylsulfoxide in a temperature range 25-65°С were studied. The concentration dependence of the reduced specific viscosity is linear. The limiting viscosity [η] value regularly decreases as temperature grows and the viscosity-average molecular weight of the polymer decreases. The Mark – Kuhn – Howink constants have been determined.

Hydrodynamic, optical, colloid-flocculating, film-forming and structural morphological properties of diluted chitosan solutions (50–640 kDa) in acetate buffer (0.33 М СН3СООН + 0.2 М СН3СOONa), both initial ones and stored for ~1,850 days, were studied. It has been established that the decrease in the intrinsic viscosity of solutions over time is manifested for the reprecipitated and high-molecular-weight samples of chitosan to a greater degree.