Detailed explanation of the viscosity of hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose gives excellent viscosity to mortar, which can significantly increase the bonding ability between mortar and base and improve the anti-sagging property of mortar, which is widely used in plastering mortar, gypsum mortar and exterior wall insulation system. The thickening effect of hydroxypropyl methylcellulose can also increase the homogeneity and anti-dispersion ability of cementitious materials, prevent the delamination, segregation and water secretion of mortar and concrete, which can be used in fiber concrete, underwater concrete and self-compacting concrete.

Recommended reading: hpmc viscosity

The viscosity of hydroxypropyl methyl cellulose comes from the viscosity of cellulose ether solution. Usually use “viscosity” as an index to evaluate the viscosity of cellulose ether solution, the viscosity of cellulose ether generally refers to a certain concentration (e.g., 2%) of cellulose ether solution, in the specified temperature (e.g., 20 ℃) and rotation rate (e.g., 20 rpm) conditions, with the specified measuring instruments (such as rotational viscometer) measured viscosity value.

Viscosity is an important parameter for evaluating the performance of cellulose ether, the higher the viscosity of hydroxypropyl methylcellulose solution, the better the viscosity of the cementitious material, the better the adhesion performance to the substrate, and the better the anti-sagging and anti-dispersing ability, but if the viscosity is too large, it will affect the fluidity of the cementitious material and the workability, Kemox has developed different products for different scenarios of applications, if you have problems in the construction, welcome to consult with us. If you have any questions about your construction, please feel free to ask us and we will be happy to answer your questions. In addition, the thickening effect of hydroxypropylmethylcellulose increases the water demand of the cementitious material, thus improving the mortar yield.

The viscosity of hydroxypropyl methyl cellulose depends on the following factors

1. The higher the polymerization degree of cellulose ether and the higher the molecular weight, the higher the viscosity of its aqueous solution;

2. The higher the dosage (or concentration) of cellulose ether, the higher the viscosity of its aqueous solution, but care should be taken to choose the right dosage when using it, so as not to over-do the dosage, which will affect the working performance of mortar and concrete;

3. Like most liquids, the viscosity of cellulose ether solution will decrease with the increase of temperature, and the higher the concentration of cellulose ether, the greater the influence of temperature;

4. Cellulose ether solutions are usually pseudoplastic with shear-thinning properties, and the higher the shear rate during testing, the lower the viscosity.

Remarks: The viscosity of mortar will be reduced by external force, which is favorable to the scraping construction of mortar, so that the mortar can have good workability and viscosity at the same time. However, the cellulose ether solution will show Newtonian fluid properties when the concentration is very low and the viscosity is very small, and the solution will gradually show pseudo-plastic fluid properties when the concentration increases, and the higher the concentration, the more obvious the pseudo-plasticity.

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