What is the recommended concentration of dispersed hydroxyethyl cellulose?

Hydroxyethyl cellulose (HEC) is a widely used water-soluble polymer with good thickening, film-forming, suspension, adhesion and other properties. It is often used in coatings, cosmetics, food and pharmaceuticals.

(1) Overview of Hydroxyethyl Cellulose

Hydroxyethyl cellulose is a chemically modified cellulose derivative with the following characteristics:

Solubility: HEC is easily soluble in cold water to form a transparent viscous solution.

Stability: Good stability to acid, alkali, heat and light.

Biocompatibility: Non-toxic, non-irritating, harmless to the human body.

Thickening ability: Able to provide significant thickening effect at low concentrations.

(2) Dispersed concentration of hydroxyethyl cellulose

The dispersed concentration of HEC refers to the amount of HEC dissolved in a certain volume of solvent, usually expressed as mass percentage (%). Different applications have different requirements for the dispersion concentration of HEC. The common dispersion concentration range is as follows:

Low viscosity solution: 0.1% - 1.0%

Medium viscosity solution: 1.0% - 2.5%

High viscosity solution: 2.5% - 5.0%

1. Paint industry

In paint, the main function of HEC is to provide thickening effect, improve the brushability and construction performance of the paint. Usually, HEC is used in paint at a concentration of 0.2% - 1.0%. The specific concentration depends on the type of paint and the required viscosity. For example, in water-based paint, the HEC concentration is usually between 0.3% - 0.5%**.

2. Cosmetic industry

In cosmetics, HEC is used to adjust the viscosity of the product, provide lubrication and stabilize the suspension system. The commonly used concentration is 0.5% - 2.0%. For example, in creams, the concentration is usually 0.5% - 1.5%, and in shampoo it is 0.2% - 0.5%.

3. Food industry

In the food industry, HEC is used as a thickener, stabilizer and emulsifier, and is commonly used in dairy products, juices, sauces, etc. The usage concentration is generally 0.5% - 2.5%. For example, in ice cream, the HEC concentration is usually between **0.3% - 1.0%**.

4. Pharmaceutical industry

In pharmaceuticals, HEC is used as a tablet binder and a controlled release matrix. Generally, the concentration is between 0.5% - 2.0%. For example, in controlled release tablets, the HEC concentration is usually 1.0% - 2.0%.

(3) Factors affecting the dispersion concentration of HEC

1. Molecular weight of HEC

The higher the molecular weight of HEC, the higher the viscosity of the solution formed. High molecular weight HEC is suitable for applications requiring higher viscosity, while low molecular weight HEC is suitable for applications with low viscosity.

2. Solution temperature

The solution temperature has a significant effect on the dissolution and dispersion of HEC. At low temperatures, HEC dissolves slowly and takes a long time to be fully dispersed; at higher temperatures, HEC dissolves faster, but too high a temperature may affect its stability.

3. pH value of the solution

HEC is sensitive to pH changes. HEC has the best solubility and stability under neutral or weakly acidic conditions (pH 6-8). Extreme acidic or alkaline environments may affect the performance and dispersion of HEC.

4. Shear rate

The dissolution and dispersion process of HEC is affected by the shear rate. Moderate stirring can promote the dissolution of HEC, but too high a shear rate may cause the solution to foam, thus affecting the use effect.

(4) Recommendations for the use of HEC

1. Dispersion process

Gradual addition: Add HEC to the solvent gradually and stir continuously to avoid agglomeration caused by excessive addition at one time.

Stirring speed: Use a moderate stirring speed to avoid foaming of the solution or uneven dispersion of HEC.

2. Dispersion medium

Water quality requirements: Use clean, impurity-free water to avoid affecting the dissolution of HEC.

Dissolution order: If the solution contains other components, such as surfactants or salts, it is recommended to dissolve HEC first and then add other components.

3. Dispersion temperature

Temperature control: Maintain an appropriate temperature (usually 20-25°C) to promote the dissolution and dispersion of HEC.

4. Storage conditions

Sealed storage: HEC should be stored in a sealed container to avoid moisture or hygroscopicity.

Environmental requirements: The storage environment should be dry and cool, avoiding high temperatures or direct sunlight.

(5) Practical application cases

1. Architectural coatings

In architectural coatings, the use of HEC improves the fluidity and construction performance of the coating. For example, a certain brand of water-based paint adds 0.4% HEC to improve the brushing effect and coating uniformity.

2. Personal care products

In personal care products, such as shampoo and conditioner, HEC is used to provide a good touch and suspension effect. A well-known brand of shampoo contains 0.3% HEC, which provides good viscosity and usage experience.

3. Food additives

In food, HEC is used as a thickener. For example, 0.6% HEC was added to a certain brand of low-fat ice cream to improve the taste and stability of the product.

The dispersion concentration of hydroxyethyl cellulose (HEC) is a key factor affecting its use effect, and the specific concentration should be adjusted according to the application field and product requirements. Generally speaking:

In coatings: 0.2% - 1.0%

In cosmetics: 0.5% - 2.0%

In food: 0.5% - 2.5%

In pharmaceuticals: 0.5% - 2.0%

When using HEC, factors such as molecular weight, solution temperature, pH value and shear rate should be considered, and appropriate dispersion methods and storage conditions should be followed to ensure optimal performance and stability. By rationally selecting and using HEC, the quality of the product and user experience can be significantly improved.