Factors Affecting the Viscosity of HPMC

Mar. 14, 2025

Hydroxypropyl Methyl Cellulose has good thickening properties in the application of mortar. It can increase the bonding ability of mortar

with the base layer and improve the anti-sagging performance of mortar. Therefore, it is widely used in plaster, EIFS mortar etc.

There are several main reasons that affect the viscosity of HPMC.

1. Molecular weight:

The higher the degree of polymerization of HPMC, the larger its molecular weight will be, resulting in a higher viscosity of its aqueous solution.

2.Temperature:

Like most liquids, the viscosity of HPMC solution decreases with increasing temperature. The higher the concentration, the greater the impact of temperature.

3. Shear rate

HPMC solution is usually a pseudoplastic body with shear-thinning characteristics. The greater the shear rate during the test, the lower its viscosity.

4.PH value

The viscosity of HPMC is relatively stable in the PH range of 6-8, and extreme acid-base environments may cause degradation, thereby reducing viscosity.

5. Concentration

The higher the amount of HPMC added or the concentration of the solution, the higher the viscosity of its aqueous solution. However, in practical applications,

the amount of HPMC should be reasonably controlled to avoid excessive dosage affecting the construction performance of mortar and concrete.

In summary, under the action of external force, the cohesion of mortar will be reduced, which helps to improve the construction convenience of mortar,

so that it can maintain good cohesion while also having good construction fluidity.

When the concentration of HPMC solution is low and the viscosity is small, its rheological behavior is close to that of Newtonian fluid; and as the concentration increases,

the solution gradually shows pseudoplastic fluid characteristics, and the higher the concentration, the more obvious the pseudoplasticity.

Factors Affecting the Viscosity of HPMC