physical property Carboxymethyl cellulose sodium (CMC) is an anionic type of cellulose, the appearance of white or slightly yellow flocculent fiber powder or white powder, no beer tasteless, non-toxic; soluble dry cold or hot water, forming a transparent solution with a certain viscosity.The solution is neutral or slightly alkaline, insoluble dry 7 alcohol 7 ether, isointernal alcohol, acetone and other organic solvents, soluble dry containing 60% water ethanol or acetone solution, temperature absorption, stable to light heat, viscosity decreases with temperature increases, the solution in PH 2~10 stable, PH low dry 2, solid precipitation, PH high dry 10 viscosity is reduced.
Discolor temperature 227℃, carbonization temperature 252℃, 2% aqueous surface tension 71mn / n. chemical property Cellulose derivatives with carboxymethyl substituents were treated with cellulose with sodium gas oxide to form alkali cellulose and then reacted with chloroacetic acid.The glucose units that constitute the cellulose have 3 hydroxyl groups that can be replaced, so the products with different degrees of displacement can be obtained.On average, 1mmol human carboxymethyl per 1q thousand heavy guide, not dissolved in water and dilute acid, but can bulge, is used for ion exchange chromatography.Carboxymethyl DKa of about 4 in pure water and 35 in 05 mol/LNaCI is weakly acidic cation exchangers, usually above dry pH4 by separation of dry neutral and basic proteins.More than 40% of the hydroxyl group is the carboxymethyl replacement of soluble dry water to form a stable high viscosity colloidal solution.
Suitable for dry beverage processing. reaction principle The main chemical reactions of CMC are the alkalization reaction of cellulose and alkali producing alkali cellulose and etherification of alkali cellulose and chlorloroacetic acid. Step 1: alkali change: [C6H7O2 (OH) 3] n + nNaOH C6H72 (OH) 2Nan + nH20 Step 1: Etherification: [C6H7O2 (OH) 2ONa] n + nCICH2COONa [C6H72 (OH) 2CH2COONa] n + nNaCI