Carboxymethyl cellulose
Other Name: CMC, carboxymethocel, cellulose glycolate
CAS number: 9000-11-7
EINECS number: 618-326-2
Appearance: White solid
Physical property:
Carboxymethyl cellulose (CMC) is an anionic cellulose, the
appearance is white or slightly yellow flocculent fiber powder or
white powder, odorless, tasteless, non-toxic; Soluble in cold water
or hot water, forming a transparent solution with a certain
viscosity. The solution is neutral or slightly alkaline, insoluble
in ethanol, isopropyl alcohol and other organic solvents, but
soluble in ethanol solution with 60% water content. It is
hygroscopic, stable to light and heat, viscosity decreases with the
increase of temperature, the solution is stable at pH 2 ~ 10, the
pH is lower than 2, there is solid precipitation, the pH value is
higher than 10 and the viscosity decreases.
Chemical property:
It is prepared from cellulose derivatives of carboxymethyl
substituents, which are treated with sodium hydroxide to form
alkali cellulose, and then reacted with monochloroacetic acid. The
glucose unit that makes up cellulose has three replaceable hydroxyl
groups, so products with different degrees of replacement can be
obtained. When 1mmol carboxymethyl is introduced per 1g dry weight
on average, it is insoluble in water and dilute acid, but can swell
and be used for ion exchange chromatography. Carboxymethyl pKa,
approximately 4 in pure water and 3.5 in 0.5mol/L NaCl, is a weakly
acidic cation exchanger, usually used for the separation of neutral
and basic proteins at pH > 4. When more than 40% hydroxyl group
is carboxymethyl, it can dissolve in water to form a stable
colloidal solution with high viscosity.
Main usage:
1, used in oil, natural gas drilling, digging and other projects
2, used in textile, printing and dyeing industry, the textile
industry will CMC as a sizing agent, used for cotton, silk,
chemical fiber, blended fabrics such as yarn sizing;
3, for the paper industry CMC in the paper industry can be used as
paper smoothing agent, sizing agent.
4, CMC added to synthetic detergent can be used as dirt adsorbent;
Daily chemical such as toothpaste industry CMC glycerol solution is
used as the glue base of toothpaste; Used as thickener and
emulsifier in pharmaceutical industry; CMC aqueous solution is used
for flotation beneficiation after viscosification.
5, used in the ceramic industry. It can be used as blank adhesive,
plasticizer, glaze suspension agent, fixing agent.
6, used in construction, improve water retention and strength
7, used in the food industry, the food industry uses high
replacement degree CMC as ice cream, canned, quick cooking noodles
thickener, beer foam stabilizer, in the processing of jam, sugar
juice, sherbet, dessert, ice cream drinks, etc., as a thickener,
binder or shape agent.
8, the pharmaceutical industry chooses appropriate viscosity CMC as
the adhesive, disintegrator of tablets, suspension aid.
