hydroxypropyl methylcellulose HPMC in Plastering MortarFebruary 2nd 2023
How to select hydroxypropyl methyl cellulose from water retention？
Water retention from hydroxypropyl methyl cellulose is one of the important properties of hydroxypropyl methyl cellulose. Factors such as air temperature, temperature and wind speed can affect the evaporation rate of moisture in cement mortar and gypsum based commodities. So in different seasons, adding hydroxypropyl methylcellulose of the same amount of commercial water retention effect has some differences.
In general, the higher the viscosity of hydroxypropyl methylcellulose, the better the water retention effect will be, but the influence of viscosity on water retention will be reduced when the viscosity exceeds 100,000 MPA.s. More than 100,000 viscosity of hydroxypropyl methylcellulose to significantly improve the water retention rate by increasing the amount of hydroxypropyl methylcellulose added to achieve.
In the detailed construction can increase or decrease the amount of hydroxypropyl methyl cellulose, adjust the water retention effect of slurry. Hydroxypropyl methyl cellulose series of products can be useful to deal with water retention at high temperature. In the high temperature season, especially the hot dry area and the thin layer construction on the sunny surface, the demand for high quality hydroxypropyl methylcellulose slurry to improve the water retention.
High quality of the uniformity of hydroxypropyl methyl cellulose, it is very good, it’s a oxygen and oxygen hydroxypropyl groups evenly distributed along the cellulose chain, it can progress the hydroxyl and ether bond on the oxygen atoms to form hydrogen bonds with water association, of free water into water, and then useful manipulation of the high temperature climate caused by moisture transpiration, reach high water retention.
High quality of hydroxypropyl methyl cellulose can evenly and usefully distractions in cement mortar and gypsum based commodities, and package all of the solid particles, and form a layer of wet membrane, the moisture in the base in the appropriate long time gradually released, and inorganic cementitious material hydration reaction, then make sure that the bonding strength and compressive strength. Therefore, in high temperature summer construction, in order to achieve water retention, according to the formula to add sufficient amount of high-quality hydroxypropyl methylcellulose products, otherwise, it will appear dry too fast and caused by insufficient hydration, strength decline, cracking, empty drum and drop quality questions, but also add workers construction difficulty. And as the temperature drops, can gradually reduce the amount of water hydroxypropyl methylcellulose added, and can reach the same water retention effect.