How to determine the quality of hydroxypropyl methyl cellulose (HPMC) in a simple and intuitive way?
A. Whiteness: Although the whiteness does not determine whether HPMC is good or not, and if the whitening agent is added in the production process, it will affect its quality. However, most of the good products have good whiteness.
B. Fineness: The fineness of HPMC is generally 80 mesh and 100 mesh, 120 mesh is less, the finer the fineness, the better the quality.
C. Transmittance: put the hydroxypropyl methyl cellulose (HPMC) into the water, after forming a transparent colloid, look at its transmittance, the greater the transmittance, the better, indicating that there are less insoluble matter.
D. Specific gravity: The greater the specific gravity, the heavier it is, the better it is. Specific gravity, generally because of the high hydroxypropyl content, and the higher the hydroxypropyl content, the better the water retention.