1. Introduction to hydroxyethyl cellulose
Hydroxyethyl cellulose (HEC) is a non-ionic water-soluble cellulose ether obtained by chemical modification of natural cellulose. HEC is widely used in coatings, construction, daily chemicals, oil fields, medicine and other fields with its excellent thickening, film-forming, moisturizing and suspending properties.

2. Properties and characteristics
Water solubility: Hydroxyethylcellulose is soluble in both cold and hot water, forming a clear or slightly turbid colloidal solution.
Thickening: It can significantly increase the viscosity of aqueous solution and has good rheological properties.
Stability: Good chemical stability, low sensitivity to acids, bases and salts.
Film Forming: Forms a clear, tough film after drying.
Moisturizing properties: Can effectively retain moisture and prevent moisture loss.
Biocompatibility: No irritation to human skin, good biodegradability.

3. Main application areas

3.1. Paint industry
Thickener: Used as a thickener in water-based coatings to provide suitable workability and leveling properties and prevent pigment settling.
Stabilizer: Prevents paint delamination and precipitation by adjusting the rheological properties of the paint.

3.2. Building materials

Cement mortar: Increase viscosity and sag resistance in cement mortar to improve construction performance and bonding strength.
Gypsum products: Used in gypsum slurries to provide excellent water retention and workability.

3.3. Daily chemicals

Detergent: Used as a thickener and stabilizer in shampoo, facial cleanser and other products to enhance product texture and usage experience.
Cosmetics: Used in lotions, gels and other products to provide stable structure and smooth texture.

3.4. Pharmaceutical field

Pharmaceutical preparations: used as binders and sustained-release materials for pharmaceutical tablets to improve drug stability and control release.
Ophthalmic products: Used in eye drops to provide appropriate viscosity and lubricity.

3.5. Oilfield industry

Drilling fluid: Used as a thickener in drilling fluid to improve the rheological properties and carrying capacity of the drilling fluid.
Fracturing fluid: Used in fracturing fluid to provide excellent viscosity and suspension to improve operating results.

4. How to use

4.1. Dissolution process

Dissolution medium: Hydroxyethyl cellulose is soluble in cold or hot water. Usually dissolves slowly in cold water but is effective.
Addition steps: Gradually add HEC to the stirring water to avoid clumping caused by adding too much at one time. First mix HEC with a small amount of water to form a paste, then gradually add the remaining water.
Stirring conditions: Use low-speed stirring to avoid bubbles caused by vigorous stirring. The mixing time depends on the specific needs, usually 30 minutes to 1 hour.

4.2. Preparation concentration

Coating Application: Typically used at concentrations of 0.2% to 1.0%.
Building Materials: Adjust to 0.2% to 0.5% as needed.
Daily chemicals: Concentration range is 0.5% to 2.0%.
Oilfield Industry: Typically 0.5% to 1.5%.

4.3. Precautions

Solution temperature: The best effect is to control the temperature at 20-40℃ during dissolution. Excessive temperatures may cause degradation.
PH value: The applicable pH range is 4-12. Pay attention to stability when using it in a strong acid or alkali environment.
Preservative treatment: HEC solutions stored for a long time need to be added with preservatives to prevent microbial growth.

4.4. Typical recipes

Coating formula: 80% water, 0.5% hydroxyethyl cellulose, 5% pigment, some additives, 15% filler.
Cement mortar formula: 65% water, 20% cement, 10% sand, 0.3% hydroxyethyl cellulose, 4.7% other additives.

5. Practical application cases

5.1. Water-based coatings:

Steps: Mix water and HEC under low-speed stirring. After HEC is completely dissolved, add pigments, additives and fillers.
Function: Increase the consistency of paint and improve fluidity and coverage during construction.

5.2. Cement mortar:

Steps: Dissolve HEC in the water used to prepare the mortar. After fully dissolving, add cement and sand and mix evenly.
Function: Improve the water retention and adhesion of mortar and enhance construction performance.

5.3. Shampoo:

Steps: Add HEC to the formula water, stir at low speed until completely dissolved, then add other active ingredients and flavors.
Function: Increase the viscosity of shampoo and provide a smooth feeling of use.

5.4. Eye drops:

Steps: Under sterile conditions, dissolve HEC in formulation water and add appropriate preservatives and other ingredients.
Function: Provide appropriate viscosity, extend the residence time of the drug in the eyes, and increase comfort.

6. Safety and environmental protection

Biodegradable: HEC is naturally degradable and environmentally friendly.
Safety: No irritation to human skin, but avoid inhalation of dust and direct contact with eyes.

Hydroxyethylcellulose is of great value in industry and daily life due to its versatility and wide range of applications. During use, it is necessary to master the correct dissolution method and proportion to give full play to its superior performance. Understanding its characteristics and precautions can effectively improve the quality and performance of the product and ensure the safety and environmental protection of the operation.