Hydroxypropyl methylcellulose five questions
1. Hydroxypropyl methylcellulose is divide into several types. What is the difference in use?
HPMC can be divided into instant type and hot-dissolved type, instant type products. It quickly disperses in cold water and disappears into water. At this time, the liquid has no viscosity, because HPMC is only disperse in water, and there is no real dissolution.
About 2 minutes, the viscosity of the liquid gradually became larger, forming a transparent white viscous colloid.
The hot-melt type product, in the case of cold water, can quickly disperse in hot water and disappear in hot water. When the temperature drops to a certain temperature, the viscosity gradually appears until a transparent viscous colloid is formed.
The hot-melt type can only be use in putty powder and mortar. In liquid glue and paint, there will be a phenomenon of clumping, which cannot be. It is available in a wide range of applications. It can be use in putty powder and mortar, as well as in liquid water and paint. There are no contraindications.
2. What is the viscosity of hydroxypropyl methylcellulose?
Putty powder is generally 100,000, the mortar is required to be higher, it is necessary to use 150,000. 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, the viscosity is lower (7-8), it is also possible.
Of course, the viscosity is larger, and the relative water retention is better. When the viscosity exceeds 100,000, the effect of viscosity on water retention is not great.
3. What are the main technical indicators of hydroxypropyl methylcellulose?
The hydroxypropyl content and viscosity, which most users care about are these two indicators. If the hydroxypropyl group content is high, the water retention is generally better, the viscosity is large, the water retention is relatively good (not the right), and the viscosity is large, and it is better use in the cement mortar.
4. What are the main raw materials of hydroxypropyl methylcellulose?
The main raw materials of HPMC: refined cotton, methyl chloride, propylene oxide, other raw materials, flake base, acid toluene.
5. What is the main role of hydroxypropyl methylcellulose in putty powder, is it chemical?
Among the putty powder, it has three functions of thickening, water retention and construction.
(1) thickening, cellulose can be thickened to suspend, so that the solution maintains uniform uniformity, and is resistant to sagging.
(2) Water retention: The putty powder is dried slowly, and the auxiliary ash calcium reacts under the action of water.
(3) Construction: Cellulose has a lubricating effect, so can make the putty powder have good construction.
HPMC does not participate in any chemical reactions and only plays a supporting role. Putty powder with water, on the wall, is a chemical reaction.
Because of the formation of new substances, the putty powder on the wall is remove from the wall. Grinding into powder, reuse, it will not work, because new substances have been formed.
If you have any questions, you can send them to my email : tanyatao@qinahaochem.com
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