Factors Affecting Water Retention of Nonionic Cellulose Ethers

Generally speaking, the viscosity of hydroxypropyl methylcellulose HPMC  is higher. However, it also depends on the degree of substitution and the average degree of substitution. Hydroxypropyl methylcellulose is a non-ionic cellulose ether. It is a white powder in appearance, odorless and tasteless. It is soluble in water and most polar organic solvents and appropriate proportions of ethanol/water, propanol/water, ethylene dichloride, etc. It is insoluble in acetone and anhydrous ethanol. It swells into a clear or slightly turbid colloidal solution in cold water. The aqueous solution is surface active and forms a film after drying. After heating and cooling, it undergoes a reversible transformation from sol to gel in sequence. High transparency and stable performance.

Hydroxypropyl methylcellulose HPMC has a thermal gelling property. The product aqueous solution forms a gel after heating and dissolves after cooling. The gelling temperature of products of different specifications is different. The solubility varies with viscosity. The lower the viscosity, the greater the solubility. The properties of hydroxypropyl methylcellulose of different specifications are different. The dissolution of hydroxypropyl methylcellulose in water is not affected by pH value.

Features: It has thickening ability, salt removal, pH stability, water retention, dimensional stability, excellent film-forming properties, and a wide range of enzyme resistance, dispersibility and adhesion.

The water retention of hydroxypropyl methylcellulose products is often affected by the following factors:

1. Hydroxypropyl methylcellulose uniformity Hydroxypropyl methylcellulose with uniform reaction, methoxy and hydroxypropoxy groups are evenly distributed, and the water retention rate is high.

2. Hydroxypropyl methylcellulose thermal gelation temperature The higher the thermal gelation temperature, the higher the water retention rate; conversely, the water retention rate is low.

3. Hydroxypropyl methylcellulose viscosity When the viscosity of hydroxypropyl methylcellulose increases, the water retention rate also increases; when the viscosity reaches a certain level, the increase in water retention rate tends to be gentle.

4. Hydroxypropyl methylcellulose addition amount The greater the amount of hydroxypropyl methylcellulose added, the higher the water retention rate and the better the water retention effect.

In the range of 0.25-0.6% addition, the water retention rate increases rapidly with the increase of addition amount; when the addition amount increases further, the increasing trend of water retention rate slows down.