The advanges of HPMC & MHEC in dry mix mortar products
November 22nd 2024Hydroxypropyl methyl cellulose hpmc for dry-mixed ready-mixed mortar
In dry-mixed ready-mixed mortar, the addition amount of hydroxypropyl methylcellulose hpmc is very low, but it can improve the performance of wet mortar and is a major additive that affects the construction performance of mortar. Reasonable selection of cellulose ethers of different varieties, different viscosities, different particle sizes, different degrees of viscosity and added amount will produce and exert an influence on the improvement of the performance of dry mortar. At present, many masonry and plastering mortars have poor water retention properties, and water slurry separation occurs after a few minutes of standing still. Water retention is an important property of methyl cellulose ether. The factors that affect the water retention effect of dry powder mortar include the amount of hydroxypropyl methyl cellulose hpmc added, the viscosity of hydroxypropyl methyl cellulose hpmc, the fineness of particles and the temperature of the environment in which it is used. Hydroxypropyl methyl cellulose hpmc is a synthetic high-molecular polymer prepared by chemical modification of natural cellulose as raw material.
The important role of water-soluble cellulose ether in mortar is mainly in three aspects. One is excellent water retention capacity, the other is the influence on the consistency and thixotropy of mortar, and the third is the interaction with cement. The water retention effect of cellulose ether depends on the water absorption of the base layer, the composition of the mortar, the layer thickness of the mortar, the water demand of the mortar, and the setting time of the coagulating material. The water retention of the cellulose ether itself comes from the solubility and dehydration of the cellulose ether itself.
In summary, in dry-mixed ready-mixed mortar, hydroxypropyl methyl cellulose ether plays a role in water retention, thickening, delaying the hydration power of cement, and improving construction performance. The good water retention capacity makes the cement hydration more complete, can improve the wet tackiness of the wet mortar, increase the bonding strength of the mortar, and the time can be adjusted. Adding hydroxypropyl methyl cellulose ether to dry-mixed mortar can improve the construction performance and structural strength of the mortar. Therefore, cellulose ether is being widely used as an important additive in dry-mixed mortar.
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