Synthesis and Flow Behavior of Sodium Carboxymethyl Starch: A Study on Viscosity and Rheology
Makhkamov M.A. Saparov S.Y. Khudoyberdiyev I.I. Gulomova I.B. Esanov R.S. Matchanov A.D. Sobirova F.A. Aimbetova E.
June 2025Engineered Science Publisher
ES Food and Agroforestry
2025#20
By chemically modifying starch in the solid phase, samples of the sodium carboxymethyl starch (Na-CMS) with degrees of substitution (DS) ranging from 0.09 to 0.95 were obtained. The viscosity of both dilute and concentrated aqueous Na-CMS solutions was analyzed using capillary and rotational viscometry. It has been shown that diluted Na-CMS solutions exhibit properties characteristic of polyelectrolytes. The rheological properties were investigated by varying the shear rate across a broad temperature range. The results indicate that concentrated Na-CMS solutions exhibit non-Newtonian behavior at all studied temperatures. The dynamic viscosity of Na-CMS solutions decreases with increasing DS, suggesting a reduction in intermolecular interactions. An increase in temperature also leads to a marked decrease in the dynamic viscosity of Na-CMS solutions. For example, for Na-CMS solutions with DS=0.74, increasing the temperature from 25 to 55 °C leads to a decrease in viscosity from 10.3 to 5.1 Pa×s. The average value of the activation energy of the viscous flow of Na-CMS solutions was determined, which is equal to 18.7 kJ/mol, indicating the presence of hydrogen bonds between polymer macromolecules.
Degree of substitution , Dynamic viscosity , Rheology , Sodium salt of carboxymethyl starch , Viscometry
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National University of Uzbekistan named after Mirzo Ulugbek, Tashkent, 100174, Uzbekistan
Institute of Pharmaceutical Education and Research, Tashkent, 100114, Uzbekistan
Institute of Bioorganic Chemistry AS RUz, Tashkent, 100125, Uzbekistan
Alfraganus University, Tashkent, 100190, Uzbekistan
Khoja Akhmet Yassawi International Kazakh-Turkish University, Turkistan, X42T8B0, Kazakhstan
Institute of Ecological Problems, Al-Farabi Kazakh National University, Al-Farabi Ave. 71, Almaty, 050040, Kazakhstan
National University of Uzbekistan named after Mirzo Ulugbek
Institute of Pharmaceutical Education and Research
Institute of Bioorganic Chemistry AS RUz
Alfraganus University
Khoja Akhmet Yassawi International Kazakh-Turkish University
Institute of Ecological Problems
10 лет помогаем публиковать статьи Международный издатель
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