The Importance of Water Retention of HPMC
April 24th 2024
Hydroxypropyl content and viscosity, most users care about these two indicators. The higher the hydroxypropyl content, the better the water retention. Viscosity is higher, water retention is relatively (rather than absolute) is better, and viscosity is higher, it is better used in cement mortar.
The most important role of hydroxypropyl methyl cellulose is to retain water, followed by thickening. In putty powder, as long as the water retention is good, the viscosity is lower (70,000 to 80,000), of course, the viscosity is higher, the relative water retention is better, when the viscosity exceeds 100,000, the effect of viscosity on water retention is Not big.
The application of putty powder: the requirement is lower, the viscosity is 100,000, and it is enough. The important thing is that the water retention is better. It plays the role of thickening, water retention and construction in the putty powder. Not involved in any response. Sometimes the reason for air bubbles is 1. Too much water is put 2. The bottom layer is not completely dry. Use high viscosity in summer and low viscosity in winter, which is more conducive to construction.
Application of mortar: higher requirements, better viscosity 150,000 or more, mortar with high viscosity is not easy to fall, it plays a role in water retention, thickening in mortar, to prevent mortar segregation, bleeding, increase the ease of mortar and construction performance .
Is there any relationship between putty powder and hydroxypropyl methylcellulose? The powder loss of putty powder is mainly related to the quality of gray calcium and not much to HPMC. The low calcium content of gray calcium and the inappropriate ratio of CaO and Ca(OH)2 in gray calcium will cause powder loss. If it has something to do with HPMC, it may cause powder loss if HPMC has poor water retention.
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