Application of hydroxypropyl methyl cellulose in putty powder
Application of hydroxypropyl methyl cellulose in putty powder
Today we lead you to understand the role of
hydroxypropyl methyl cellulose in putty powder, in general, there are thickening, water retention and construction of three roles.
Thickening: cellulose can be thickened to suspension, so that the solution remains uniform up and down the role of anti-hanging.
Water retention: make putty powder dry slowly, assist the reaction of ash calcium under the action of water.
Construction: cellulose has lubrication effect, can let putty powder has good construction.
Hydroxypropyl methyl cellulose HPMC does not participate in any chemical reaction, only plays an auxiliary role.Putty powder with water, on the wall, is a chemical reaction, because of the generation of new substances, the putty powder on the wall from the wall down, ground into powder, reuse, not good, because has formed a new substance (calcium carbonate).The main components of grey 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 grey calcium under the action of water and CO2 in the air, the formation of calcium carbonate, and
HPMC is only water retention, assist the better reaction of grey calcium, it itself does not participate in any reaction.
Putty powder is generally one hundred thousand can, the requirement in mortar is some higher, want one hundred fifty thousand ability to use.Moreover, the most important role of HPMC is to retain water, followed by thickening.In putty powder, as long as the water retention is good and the viscosity is low (7-80 thousand), it is also possible. Of course, the viscosity is larger and the relative water retention is better. When the viscosity is more than 100 thousand, the viscosity has little effect on the water retention.
