The main indicators to measure the quality of sodium carboxymethyl cellulose CMC are the degree of substitution (DS) and purity.
Generally, the properties of sodium carboxymethyl cellulose CMC are different when the DS is different; the higher the degree of substitution, the better the solubility, and the better the transparency and stability of the solution. When the CMC substitution degree of sodium carboxymethyl cellulose is 0.7-1.2, the transparency is better, and the viscosity of its aqueous solution is the largest when the pH value is 6-9.
In order to ensure its quality, in addition to the selection of etherifying agent, some factors that affect the degree of substitution and purity must also be considered, such as the dosage relationship between alkali and etherifying agent, etherification time, system water content, temperature, DH value, solution. concentration and salt.