What is the difference between cellulose ether and cellulose?

Cellulose and cellulose ether are both derived from cellulose, a natural polymer found in the cell walls of plants. However, they have distinct differences in their chemical structures and properties:

1. Chemical Structure: Cellulose is a linear polysaccharide consisting of repeating glucose units linked together by β(1→4) glycosidic bonds. It is a straight-chain polymer with a high degree of crystallinity.
2. Hydrophilicity: Cellulose is inherently hydrophilic, meaning it has a strong affinity for water and can absorb significant amounts of moisture. This property influences its behavior in various applications, including its interaction with water-based systems such as cement mixtures.
3. Solubility: Pure cellulose is insoluble in water and most organic solvents due to its highly crystalline structure and extensive hydrogen bonding between polymer chains.
4. Derivatization: Cellulose ether is a modified form of cellulose obtained through chemical derivatization. This process involves introducing functional groups, such as hydroxyethyl, hydroxypropyl, methyl, or carboxymethyl groups, onto the cellulose backbone. These modifications alter the properties of cellulose, including its solubility, rheological behavior, and interaction with other substances.
5. Solubility in Water: Cellulose ethers are typically soluble or dispersible in water, depending on the specific type and degree of substitution. This solubility makes them highly useful in various industries, including pharmaceuticals, food, cosmetics, and construction.
6. Application: Cellulose ethers find widespread application as thickening agents, stabilizers, binders, and film-forming agents in a diverse range of products and processes. In construction, they are commonly used as additives in cement-based materials to improve workability, water retention, adhesion, and other properties.

In summary, while cellulose and cellulose ether share a common origin, cellulose ether is chemically modified to introduce specific properties that make it soluble or dispersible in water and suitable for various applications where control over rheological behavior and interaction with other substances is desired.