What is the main role of HPMC in the application of putty powder?
November 6th 2024
HPMC has three functions of thickening, water retention and construction in the application of putty powder. Thickening: cellulose can thicken, play a role in suspension, keep the solution uniform up and down, and resist sagging. Water retention: make putty powder dry slowly, and assist lime calcium to react under the action of water. Construction: cellulose has lubricating effect, which can make putty powder have good workability. HPMC does not participate in any chemical reaction, but only plays an auxiliary role. Adding water to the putty powder and putting it on the wall is a chemical reaction, because there is the formation of new substances. Take the putty powder off the wall, grind it into powder, and then use it, it won’t work, because a new substance (calcium carbonate) has been formed. The main components of lime calcium powder are: a mixture of Ca (OH) 2, Cao and a small amount of CaCO3, cao+h2o=ca (OH) 2-Ca (OH) 2 + co2=caco3 ↓ +h2o lime calcium generates calcium carbonate under the action of CO2 in water and air, while HPMC only retains water and assists lime calcium in better reaction, and it itself does not participate in any reaction.
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