Hydroxypropyl methylcellulose and hydroxyethyl cellulose are both cellulose, so what is the difference between them?

Hydroxypropyl methylcellulose (HPMC), also known as hydroxypropyl methylcellulose, is a type of non-ionic cellulose mixed ether. It is a semi-synthetic, inactive, viscoelastic polymer, often used as a lubricant in ophthalmology, or as an excipient or excipient in oral drugs.

Hydroxyethyl cellulose (HEC), chemical formula (C2H6O2)n, is a white or light yellow, odorless, non-toxic fibrous or powdered solid, prepared by etherification reaction of alkaline cellulose and ethylene oxide (or chloroethanol), and belongs to non-ionic soluble cellulose ethers. Due to its good thickening, suspension, dispersion, emulsification, adhesion, film formation, moisture protection and protective colloid properties, HEC has been widely used in oil extraction, coatings, construction, medicine and food, textiles, papermaking, and polymer polymerization reactions. The 40 mesh sieving rate is ≥99%.

 

Although both are cellulose, there are many differences between the two:

Hydroxypropyl methylcellulose and hydroxyethyl cellulose have differences in properties, uses and solubility.

1. Different characteristics

Hydroxypropyl methylcellulose: (HPMC) is a white or white-like fiber or granular powder, belonging to various non-ionic cellulose mixed ethers. It is a semi-synthetic inactive viscoelastic polymer.

Hydroxyethyl cellulose: (HEC) is a white or yellow, odorless and non-toxic fiber or powder solid. It is etherified by alkaline cellulose and ethylene oxide (or chloroethanol). It belongs to non-ionic soluble cellulose ether.

2. Different solubility.

Hydroxypropyl methylcellulose: Almost insoluble in anhydrous ethanol, ether and acetone. Soluble in cold water as a clear or slightly turbid colloidal solution

Hydroxyethyl cellulose: It has the characteristics of thickening, suspension, bonding, emulsification, dispersion, and moisturizing. It can prepare solutions with different viscosity ranges and has excellent salt solubility for electrolytes.

Hydroxypropyl methylcellulose has the characteristics of thickening ability, low salt tolerance, pH stability, water retention, dimensional stability, excellent film-forming properties, wide enzyme resistance, dispersibility and bonding.

There are many differences between the two, and their uses in the industry are also quite different.

Hydroxypropyl methylcellulose is mostly used as a thickener, dispersant and stabilizer in the coating industry, and has good solubility in water or organic solvents. In the construction industry, it is used in cement, gypsum, latex putty, plaster, etc., which can improve the dispersibility of cement sand and greatly improve the plasticity and water retention of mortar.

Hydroxyethyl cellulose has the characteristics of thickening, suspension, bonding, emulsification, dispersion, and moisturizing. It can prepare solutions with different viscosity ranges and has excellent salt solubility for electrolytes. Hydroxyethyl cellulose is an effective film former, adhesive, thickener, stabilizer and dispersant in shampoo, hair spray, neutralizer, hair conditioner and cosmetics; it is a dirt redeposition agent in detergent powder. Hydroxyethyl cellulose dissolves quickly at high temperatures, which can speed up the production process and improve production efficiency. The obvious feature of detergents containing hydroxyethyl cellulose is that it can improve the smoothness and mercerization of fabrics.

Hydroxyethyl cellulose can also be used in building products such as concrete mixes, fresh mortar, stone plaster or other mastics to retain water during the construction process before they set and harden. In addition to improving the water retention of building products, hydroxyethyl cellulose can also extend the correction and open time of plaster or mastic. It can reduce crusting, slippage and sagging. This can improve construction performance, increase work efficiency, save time, and also increase the volume expansion rate of plaster, thereby saving raw materials.