Hydroxypropyl Methyl Cellulose(HPMC) problems
1. What are the main technical indicators of HPMC?
The hydroxypropyl content and viscosity, which most users care about are these two indicators. If the hydroxypropyl content is high, the water retention is generally better.
2. What is the viscosity of HPMC?
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 the putty powder, as long as the water retention is good, the viscosity is lower.
3. What are the main raw materials of HPMC?
The main raw materials of HPMC: refined cotton, methyl chloride, propylene oxide, other raw materials, such as caustic soda, acid, toluene, isopropanol.
4. The application of HPMC in putty powder, what is the main role, is there a chemical?
In the putty powder, HPMC plays the role of thickening, water retention and construction. Thickening: Cellulose can be thickened to suspend, keep the solution uniform and uniform, and resistant to sagging. Water retention: The putty powder is dried slowly, and the auxiliary ash calcium reacts under the action of water.
Construction: Cellulose has a lubricating effect, which can make the putty powder have good workability. 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 new substances have been formed. HPMC only retains water and aids in the better reaction of ash calcium, which itself does not participate in any reaction.
5. HPMC is a non-ionic cellulose ether, so what is non-ion?
Generally speaking, non-ion is a substance that does not ionize in water.
6. Does the powder of putty powder have any relationship with HPMC?
The powder of putty powder is mainly related to the quality of gray calcium, and has little to do with HPMC. The low calcium content of gray calcium and the inappropriate ratio of CaO and Ca(OH)2 in gray calcium can cause powder loss.
7. What is the gel temperature of hydroxypropyl methylcellulose?
The gel temperature of HPMC is related to its methoxy content, the methoxy content is low, and the gel temperature is higher.
8. How to choose the right HPMC for different purposes?
Application of putty powder: lower requirements, viscosity of 100,000, it is ok, it is important to keep water. Application of mortar: high requirements, high viscosity, 150,000 is better. Glue application: Need instant type product, high viscosity.
9. What is the difference between the cold water instant type and the hot melt type of HPMC in the production process?
HPMC’s cold water-soluble type is surface treated with glyoxal and dispersed rapidly in cold water, but it is not really dissolved. When the viscosity comes up, it dissolves. The hot soluble form is not surface treated with glyoxal. When the amount of glyoxal is large, the dispersion is fast, but the viscosity is slow, and the amount is small.
10. What is the smell of HPMC ?
The HPMC produced by the solvent method uses toluene and isopropyl alcohol as a solvent. If the washing is not very good, there will be some residual taste.
11. The relationship between viscosity and temperature of HPMC, what should be paid attention to in practical application?
The viscosity of HPMC is inversely proportional to temperature, that is, the viscosity increases with decreasing temperature. The viscosity of a product we usually refer to is the result of a 2% aqueous solution at a temperature of 20 degrees Celsius.
12. The application of HPMC in putty powder, what is the cause of foam in putty powder?
In the putty powder, HPMC plays the role of thickening, water retention and construction. Do not participate in any reaction.
The reason for the bubble: 1. Put too much water. 2. The bottom layer is not dry, just scrape a layer on it, and it is easy to foam.