Basic properties of sodium carboxymethyl cellulose CMC
Most of the cmc is high-quality pseudoplastic, and some production varieties are almost solid and gelatinous, and vigorous stirring can make it watery. Carboxymethyl cellulose often exhibits pseudoplastic behavior, or shear thinning. Such transitions are not immediate and are a gradual process.
The shear force needs to be applied continuously until the shear force is reduced. When the shear force disappears, the shear force concession slowly returns to its original shape. Sodium carboxymethyl cellulose also has good solubility characteristics, and the solvent characteristics of commodities with different degrees of substitution are different.
When neutral carboxymethyl cellulose is dissolved in water, in view of the rejection effect between anions, the linear structure of the macromolecular chain is rare and curly, CMC is the kind of weak acid salt, if the pH value is continuously reduced, according to the reagent The amount of acidity and substitution will produce different levels of precipitation.
The repulsion between carboxyl groups will be weakened in a strong alkaline environment, because the presence of alkali metal anions causes the molecular chain to bend, which reduces the viscosity of the reagent.
Because of this, the viscosity of carboxymethyl cellulose solution depends on its pH value. When the pH value of high-viscosity CMC is between 6-8, the viscosity shows the largest value.
In the process of configuring sodium carboxymethyl cellulose, our usual practice is relatively simple, but there are several that cannot be configured together.
First of all, it is strong acid and strong alkali. If this solution is mixed with sodium carboxymethyl cellulose, it will cause fundamental damage to sodium carboxymethyl cellulose;
Secondly, all heavy metals cannot be configured;
In addition, sodium carboxymethyl cellulose will never be mixed with organic chemicals, so we should not fuse sodium carboxymethyl cellulose with ethanol, because precipitation will definitely occur;
It should be noted that if sodium carboxymethyl cellulose reacts with gelatin or pectin, it is very easy to produce coagglomerates.
The above are some of the things we need to pay attention to when configuring sodium carboxymethyl cellulose. Generally speaking, when we are configuring, we only need to react sodium carboxymethyl cellulose with water.
Pay attention to the storage of sodium carboxymethyl cellulose
1. Moisture-proof: Because sodium carboxymethyl cellulose is easily soluble in water, and its raw material itself has very good hygroscopicity, it should be stored in a dry and ventilated warehouse to avoid damage to the packaging bag, and it must be protected from moisture and rain. , so as to ensure that its characters will not change, so as to avoid unnecessary losses.
2. High temperature resistance: When the temperature of sodium carboxymethyl cellulose reaches a high level, the color will begin to change, and the performance and properties of sodium carboxymethyl cellulose will be more or less affected under the influence of high temperature. , therefore, be sure to avoid high temperatures when storing.
3. Fire prevention: Since sodium carboxymethyl cellulose is a flammable organic substance, once it encounters fire, it will not be able to continue to be used under the influence of fire, so special attention should be paid to fire prevention when storing.
Post time: Nov-10-2022