Sodium CarboxymethylCellulose (Sodium CMC) product is a kind of important Cellulose ether , a polyanion product with good water solubility obtained from plant fiber by means of chemical modification. It is easily soluble in cold water and has dispersibility. Moreover, it has some very unusual physical and chemical properties such as being difficult to get bad and being physiologically harmless.
Sodium CMC (Sodium CarboxymethylCellulose) has very unusual and valuable physical and chemical properties such as emulsifying dispersion and solid dispersion properties, as well as being difficult to get bad and being physiologically harmless. It is a natural polymer derivative with wide application. sodium cmc has many excellent properties such as thickening, dispersing, suspending, adhesive, colloid protecting and water-retaining properties, widely used in food, medicine and toothpaste industries. sodium cmc is a kind of macromolecular chemical substance and can absorb water and swell. When it swells in water, it can form transparent thick solution. It is neutral in pH value.
Sodium CMC is white or slightly yellowish fibrous powder, or white powder in appearance. It is odorless, tasteless, non-toxic, easily soluble in cold or hot water to form colloid and the solution is neutral or slightly alkaline. However, it is insoluble in organic solvents such as ethanol, diethyl ether, isopropanol and acetone but soluble in ethanol or acetone solutions containing 60% water. Besides, it has hygroscopicity and stability to light and heat. The viscosity decreases with the rise of temperature. In the pH value 2-10, the solution is stable; when the pH value is lower than 2, it will separate out solids; if the pH value is higher than 10, the viscosity will decrease. The thermo-chromic temperature is 227℃ and the carbonization temperature is 252℃. The surface tension of 2% aqueous solution is 71mn/n.
The main physical and chemical indicators of sodium carboxymethyl cellulose products are the viscosity, DS (degree of substitute), pH value, purity and heavy metals.
Solubility of sodium cmc
Sodium CMC is a natural hydrophilic substance and when sodium carboxymethyl cellulose particles disperse in water, it will immediately swell and then dissolve.
1. Under the condition of stirring, adding sodium cmc slowly helps to accelerate dissolution.
2. Under the condition of heating, adding sodium cmc dispersedly can increase the dissolution rate, but the heating temperature cannot be too high and is appropriate within 50-60°C.
3. If it is used by blending with other materials, first mix the solids together and then dissolve, and in this way, the dissolution speed can also be enhanced.
4. Add a kind of organic solvents which are insoluble with sodium cmc but soluble with water such as ethanol and glycerin and then dissolve, so in this way, the solution speed can be very fast.
Aspects of Determining the Time Needed for Complete Dissolution of sodium cmc
1. sodium cmc can totally conglutinate with water and there doesn’t exist solid-liquid separation phenomenon between the two.
2. The mixed thick colloid is in a uniform state and the surface is flat and smooth.
3. The mixed thick colloid is nearly colorless transparent in color and have no particles in it.
From the moment sodium cmc is put into the pill tank and mix with water to the time sodium cmc is completely dissolved, it may take 10-20 hours.
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