Introduction to Hydroxyethyl Methylcellulose HEMC

Basic information about hydroxyethyl methylcellulose

Molecule: C2H6O2 xCH4O x PhEur 2002 defines hydroxyethylmethylcellulose as partially O-methylated, partially O-hydroxymethylated cellulose. The different specifications are expressed as apparent viscosity in mPa·s of a 2% w/v aqueous solution at 20°C.

Molecular weight: PhEur 2002 defines hydroxyethylmethylcellulose as partially O-methylated, partially O-hydroxymethylated cellulose. The different specifications are expressed as apparent viscosity in mPa·s of a 2% w/v aqueous solution at 20°C.

The main features of hydroxyethyl methylcellulose (HEMC) are:

1. Solubility: soluble in water and some organic solvents. HEMC is soluble in cold water. Its maximum concentration is determined only by viscosity. Solubility changes with viscosity. The lower the viscosity, the greater the solubility.

2. Salt resistance: HEMC products are nonionic cellulose ethers, not polyelectrolytes. Therefore, they are relatively stable in aqueous solutions in the presence of metal salts or organic electrolytes. However, adding too much electrolytes will cause gelation and precipitation.

3. Surface activity: Because the aqueous solution has surface activity, it can be used as a colloidal protective agent, emulsifier, and dispersant.

4. Thermal gelation: When the HEMC product aqueous solution is heated to a certain temperature, it becomes opaque, gels, and forms a precipitate. However, when it continues to cool, it returns to the original solution state. This kind of gelation and precipitation occurs. The temperature mainly depends on their lubricants, suspension aids, protective colloids, emulsifiers, etc.

5. Metabolic inertness, low odor and low aroma: HEMC is widely used in food and medicine because it is not metabolized, has low odor and low aroma.

6. Antifungal: HEMC has good antifungal ability and good viscosity stability during long-term storage.

7. PH stability: The viscosity of the aqueous solution of HEMC products is almost unaffected by acid and alkali, and the pH value is relatively stable in the range of 3.0-11.0.

Usage: Due to the surface activity of aqueous solution, hydroxyethyl methylcellulose can be used as a colloidal protective agent, emulsifier and dispersant. Examples of its application are as follows: Effect of hydroxyethyl methylcellulose on cement properties. Hydroxyethylmethylcellulose is an odorless, tasteless, non-toxic white powder that dissolves in cold water to form a clear, viscous solution. It has the properties of thickening, bonding, dispersing, emulsifying, film-forming, suspending, adsorption, gelling, surface activity, moisturizing, and protective colloid. Because the aqueous solution has a surface-active effect, it can be used as a colloidal protective agent, emulsifier and dispersant. Hydroxyethylmethylcellulose aqueous solution has good hydrophilicity and is an efficient water retention agent.