Sodium carboxymethyl cellulose (CMC-Na for short) is an important water-soluble polymer compound, widely used in food, medicine, cosmetics, textile, papermaking and construction industries. As a commonly used thickener, stabilizer and emulsifier,
1. Raw material selection and quality control
When selecting CMC-Na, you should pay attention to choosing high-purity products. The quality indicators of the product include degree of substitution, viscosity, purity and pH value. The degree of substitution refers to the content of carboxylmethyl groups in the CMC-Na molecule. Generally, the higher the degree of substitution, the better the solubility. Viscosity determines the consistency of the solution, and the appropriate viscosity grade should be selected according to the actual application requirements. In addition, ensure that the product has no odor, no impurities, and meets relevant standards, such as food grade, pharmaceutical grade, etc.
2. Water quality requirements for preparing the solution
When preparing CMC-Na solution, the quality of the water used is very critical. It is usually required to use pure water or deionized water to avoid the influence of impurities in the water on the CMC-Na solution. Impurities such as metal ions and chloride ions in water may react chemically with CMC-Na, affecting the stability and performance of the solution.
3. Dissolution method and steps
The dissolution of CMC-Na is a slow process, which usually needs to be carried out in steps:
Pre-wetting: Before adding CMC-Na powder to water, it is recommended to pre-wet it with a small amount of ethanol, propylene glycol or glycerol. This helps prevent the powder from agglomerating during the dissolution process and forming an uneven solution.
Slow feeding: Slowly add CMC-Na powder under stirring conditions. Try to avoid adding a large amount of powder at one time to avoid the formation of lumps and difficulty in dissolving.
Full stirring: After adding the powder, continue stirring until it is completely dissolved. The stirring speed should not be too fast to prevent the generation of too many bubbles and affect the transparency of the solution.
Temperature control: The temperature during the dissolution process has a certain effect on the dissolution rate. Generally speaking, the temperature between 20°C and 60°C is more suitable. Too high a temperature may cause the solution viscosity to decrease and even destroy the structure of CMC-Na.
4. Storage and stability of solution
The prepared CMC-Na solution should be stored in a sealed container and avoid contact with air to prevent moisture absorption and oxidation. At the same time, direct sunlight and high temperature environment should be avoided as much as possible to maintain the stability of the solution. During long-term storage, the solution may deteriorate due to the growth of microorganisms, so you can consider adding preservatives such as sodium benzoate and potassium sorbate when preparing it.
5. Use and treatment of solution
When using CMC-Na solution, you should be careful to avoid contact with strong acids and strong bases to avoid chemical reactions that affect the stability and performance of the solution. In addition, CMC-Na solution is irritating to the skin and eyes to a certain extent, so you should wear appropriate protective equipment when using it, such as gloves, goggles, etc.
6. Environmental protection and waste disposal
When using CMC-Na, you should pay attention to the environmental protection of waste. Waste CMC-Na solution should be handled in accordance with relevant regulations to avoid pollution to the environment. Waste can usually be treated by biodegradation or chemical treatment.
When preparing sodium carboxymethyl cellulose solution, it is necessary to carefully consider and operate from multiple aspects such as raw material selection, dissolution method, storage conditions and environmental protection treatment. Only under the premise of strict control of each link can the prepared solution have good performance and stability to meet the needs of different application fields.