The Chinese name of HPMC is hydroxypropyl methylcellulose, which is non-ionic. It is often used as a water-retaining agent in dry-mixed mortar and is the most commonly used water-retaining material in mortar.
The production process of HPMC is mainly a polysaccharide ether product produced by alkalization and etherification of cotton fiber (domestic). It has no charge itself, does not react with charged ions in the gelling material, and has stable performance. The price is also lower than other types of cellulose ethers, so it is widely used in dry mix mortar.
HPMC function: It can thicken the fresh mortar to have a certain wet viscosity and prevent segregation. (Thickening) Water retention is also the most important property, helping to maintain the amount of free water in the mortar, giving the cementitious material more time to hydrate after the mortar is applied. (Water retention) It has air-entraining properties, which can introduce uniform and fine air bubbles to improve the workability of mortar.
The higher the viscosity of HPMC, the better the water retention performance. Viscosity is an important parameter of HPMC performance. At present, different HPMC manufacturers use different methods and instruments to measure the viscosity of HPMC. The main methods are HaakeRotovisko, Hoppler, Ubbelohde and Brookfield.