Factors affecting the viscosity of hydroxypropyl methylcellulose (HPMC)

Hydroxypropyl methylcellulose (HPMC)is one of our best-selling products, offering a low price and high quality. It can be used as a thickening and water-retaining agent in building mortars. Shijiazhuang Cellulose Co., Ltd. is a cellulose manufacturer from China and can provide you with a sufficient supply.

Hydroxypropyl methylcellulose (HPMC)exhibits excellent thickening properties in wet mortar applications, significantly increasing the adhesion between the wet mortar and the substrate. It also improves the sag resistance of the mortar, making it widely used in rendering mortars, external wall insulation systems, and tile adhesives.

The thickening effect of HPMC also increases the homogeneity and anti-segregation properties of fresh cement-based materials, preventing stratification, segregation, and bleeding in mortars and concrete. It can be used in fiber-reinforced concrete, underwater concrete, and self-compacting concrete.

The viscosity of HPMC depends mainly on the following factors:

1. Like most liquids, the viscosity of HPMC solutions decreases with increasing temperature. The higher the concentration of HPMC, the greater the effect of temperature.

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

3. HPMC solutions are usually pseudoplastic fluids, exhibiting shear-thinning properties. The higher the shear rate during testing, the lower the viscosity.

4. The higher the HPMC content or concentration, the higher the viscosity of its aqueous solution. However, it is important to choose an appropriate dosage to avoid affecting the workability of the mortar and concrete if the dosage is too high.

In summary, the cohesiveness of the mortar decreases under external forces, which facilitates the troweling and application of the mortar, resulting in mortar with both good cohesiveness and workability.

At low concentrations and low viscosity, HPMC solutions exhibit Newtonian fluid characteristics. As the concentration increases, the solution gradually exhibits pseudoplastic fluid characteristics, and the higher the concentration, the more pronounced the pseudoplasticity.