2025-02-24- readings1. Definition of cellulose ethers
Cellulose ethers are derivatives of natural cellulose, produced by etherification reactions. Cellulose is the main component of plant cell walls and is abundant in nature. Cotton contains nearly 100% cellulose and wood contains 40-50% cellulose. Each glucose unit in cellulose has three hydroxyl groups, which can be etherified to increase solubility and give it unique properties.
2. Properties of cellulose ethers
(1) Solution properties
Thickening: Increases viscosity in applications such as cement mortar, coatings and food, enhancing stability and texture.
Water solubility: Forms clear solutions, ideal for pharmaceuticals and personal care products.
Suspension stability: Prevents particle aggregation in latex paints and ceramic glazes, ensuring uniformity.
(2) Physical and chemical properties
Film-forming: Forms a protective film in pharmaceutical coatings and food packaging, extending shelf life.
Water retention: Retains moisture in building materials such as cement and gypsum to prevent cracking.
Adhesion: Improves adhesion of building materials and textiles, increasing strength and durability.
Colloid protection: Stabilizes colloidal systems in pharmaceuticals and foods to ensure consistent performance.
(3) Other properties
Biocompatibility: Non-toxic and odorless, suitable for food, pharmaceuticals and cosmetics.
Stability: Maintains performance at different temperatures and pH values.
3. Applications of cellulose ethers
(1) Construction
Mortar additives: Enhances water retention, processability and adhesion of cement and gypsum mortars.
PVC production: As a dispersant, improves resin quality and thermal stability.
(2) Pharmaceuticals
Excipients: Used in drug coatings, sustained-release preparations and tablet adhesives.
Drug delivery: Achieve targeted drug release, improve efficacy and reduce side effects.
(3) Food industry
Thickening and stabilization: Enhances the texture and stability of sauces, beverages and baked goods.
Moisturizing: Improves the juiciness of processed meats and gel formation in desserts.
(4) Personal Care
Thickening and Emulsification: Used in shampoos, lotions and cosmetics to improve texture and stability.
(5) Other Industries
Oil Extraction: Enhance drilling fluid viscosity and well stability.
Textiles and Paper: Improve fabric strength and paper water resistance.
Leather Processing: Improve tanning and finishing quality.
4. Classification of Cellulose Ethers
By ionization: Ionic (e.g. CMC) and non-ionic (e.g. HPMC) types have different uses.
By substituent: Monoether (e.g. MC) and mixed ether (e.g. HPMC) have different properties.
By solubility: Water-soluble (e.g. HPMC) and water-insoluble (e.g. EC) types are suitable for various industrial uses.
5. Production Process
Alkalization: React cellulose with sodium hydroxide to activate hydroxyl groups.
Etherification: Introduce etherifying agents (e.g. propylene oxide) to produce specific cellulose ethers.
Post-processing: neutralization, washing, drying and pulverization to obtain the final product.
Cellulose ether is a widely used polymer that provides solutions for construction, pharmaceuticals, food, etc. Its unique properties, such as thickening, water retention and biocompatibility, make it an indispensable part of modern industry.
