The role of hydroxypropylmethylcellulose in wet-mixed mortar

Wet-mixed mortars are cement, fine aggregates, additives and water, and various components are determined according to their properties.After the mixing is measured in a certain proportion at the mixing station, the mixture is transported to the place of use by a mixing truck and stored in a special container, and the wet mixture is used within the specified time.

Hydroxypropylmethylcellulose is used as a water retaining agent and a retarder for cement mortar to make mortar that can be pumped.In the mortar used as an adhesive, in order to improve the spreadability and extend the operating time, the water retention of hydroxypropylmethylcellulose HPMC will not cause the slurry to break due to excessive drying after coating, and the strength after hardening is improved.Water retention is an important property of hydroxypropylmethylcellulose HPMC, and it is also the performance of many wet mixed mortar manufacturers in China.Factors that affect the water retention effect of wet-mixed mortar include the amount of HPMC added, the viscosity of HPMC, the fineness of the particles, and the temperature of the use environment.

The important role of hydroxypropylmethylcellulose HPMC in wet-mixed mortar is mainly manifested in three aspects, one is the excellent water retention performance, the other is the effect on the consistency and thixotropic properties of wet-mixed mortar, and the third is the interaction with cement.Cellulose ether has a good water retention effect. Taking it depends on the water absorption rate of the base layer, the composition of the mortar, the layer thickness of the mortar, the water demand of the mortar and the condensation time of the solidified material.The higher the transparency of hydroxypropylmethylcellulose, the better the water retention.

Factors that affect the water retention of wet-mixed mortar include the viscosity of cellulose ether, the amount added, the particle fineness and the temperature of use.The greater the viscosity of cellulose ether, the better the water retention.Viscosity is an important parameter of HPMC performance.For the same product, the viscosity results measured by different methods vary greatly, and some are even twice the difference.Therefore, when comparing viscosities, it must be carried out between the same test methods, including temperature, rotor, etc.

Generally speaking, the higher the viscosity, the better the water retention effect.However, the higher the viscosity, the higher the molecular weight of HPMC, and its solubility will be reduced accordingly, which has a negative impact on the strength and construction performance of the mortar.The higher the viscosity, the more obvious the thickening effect of the mortar, but it is disproportionate.The higher the viscosity, the higher the viscosity of the wet mortar, and when used, it will exhibit adhesion and high adhesion to the substrate.However, increasing the structural strength of the wet mortar itself is not helpful.During construction, the anti-sagging performance is not obvious.On the contrary, some low-viscosity but modified hydroxypropylmethylcellulose has excellent properties to improve the structural strength of wet mortars.

The more cellulose ether HPMC is added to the wet-mixed mortar, the better the water retention performance, and the higher the viscosity, the better the water retention performance.Fineness is also an important performance indicator of hydroxypropylmethylcellulose.

The fineness of hydroxypropylmethylcellulose also has a certain effect on its water retention.Generally speaking, for hydroxypropylmethylcellulose with the same viscosity and different fineness, the finer the fineness, the smaller the fineness.The water retention effect is better.

In wet mixed mortar, the amount of cellulose ether HPMC added is very low, but it can significantly improve the construction performance of wet mixed mortar, which is the main additive that affects the construction performance of mortar.The correct choice of hydroxypropylmethylcellulose has a great impact on the performance of wet-mixed mortar.