HPMC name hydroxypropyl methylcellulose, for non-ionic type, in dry mixed mortar is commonly used as water retention agent, thickener, pumping agent, lubricant, etc., is the most commonly used water retention material in mortar.
HPMC production process is mainly cotton fiber after alkalization, etherification and the generation of polysaccharide ether products. It has no charge and does not react with the charged ions in the cementing material, so its performance is stable. The price is also lower than other types of cellulose ether, so it is widely used in dry mixed mortar.
Hydroxypropyl methylcellulose function: can make the new mix mortar thickened so that there is a certain wet viscosity, to prevent segregation. Water retention is also the most important property, helping to maintain the amount of free water in the mortar so that the cementing material has more time to hydrate after mortar construction. (water retention) its own air suction, can introduce uniform fine bubbles, improve the construction of mortar.
The higher the viscosity of hydroxypropyl methylcellulose ether, the better the water retention performance. Viscosity is an important parameter of HPMC performance. At present, different HPMC manufacturers adopt different methods and instruments to measure the viscosity of HPMC, and the main methods include HaakeRotovisko, Hoppler, Ubbelohde and Brookfield.