Factors affecting the water retention of hydroxypropyl methyl cellulose (HPMC)

Generally speaking, the viscosity of hydroxypropyl methy?lcellulose?(HPMC)?is higher, but it also depends on the degree of substitution and the average degree of substitution. Hydroxypropyl methyl?cellulose?(HPMC)?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., 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.

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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 HPMC?of different specifications are different. The dissolution of HPMC?in water is not affected by pH value.

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

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The water retention of HPMC itself is often affected by the following factors:

1. HPMC uniformity

HPMC with uniform reaction has uniform distribution of methoxy and hydroxypropoxy groups and high water retention rate.

2. HPMC thermal gelation temperature

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

3. HPMC viscosity

When the viscosity of HPMC increases, the water retention rate also increases; when the viscosity reaches a certain level, the increase in water retention rate tends to be flat.

4. HPMC addition amount

The larger the amount of HPMC 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 the addition amount; when the addition amount increases further, the increase trend of the water retention rate slows down.