All questions about Hydroxypropyl Methylcellulose(HPMC), all here!
All questions about Hydroxypropyl Methylcellulose(HPMC), all here!(2)
8.What are the main raw materials of hydroxypropyl methyl cellulose (HPMC)?
A: The main raw materials of hydroxypropyl methyl cellulose (HPMC) are: refined cotton, chloromethane and propylene oxide.
9. What is the main role of HPMC in putty powder and does it occur chemically?
–A: HPMC plays three roles in putty powder: thickening, water retention and construction. Thickening: the cellulose thickens the putty and keeps the solution in suspension, evenly up and down, and resists sagging.
Water retention: It makes the putty powder dry more slowly and assists the reaction of calcium grey under the action of water.
Construction: Cellulose has a lubricating effect and allows the putty powder to work well, HPMC does not react chemically and only plays an auxiliary role.
Putty powder with water, on the wall, is a chemical reaction, because a new substance is created. The main components of calcium grey powder are: Ca(OH)2, CaO and a small amount of CaCO3, CaO+H2O=Ca(OH)2 -Ca(OH)2+CO2=CaCO3+H2O Calcium grey is produced by the action of water and CO2 in the air. It does not participate in any reaction.
10、What does the gel temperature of HPMC have to do with?
–A: The gel temperature of HPMC is not related to its methoxy content, the lower the methoxy content, the higher the gel temperature.
11、Is there any relationship between the powder falling off of putty powder and HPMC?
–A: The powdering of putty powder is mainly related to the quality of calcium ash, but not to HPMC. The low calcium content of calcium ash and the inappropriate ratio of CaO and Ca(OH)2 in calcium ash will cause the powder to fall off. If it has anything to do with HPMC, it is the poor water retention of HPMC that can cause powdering, see question 9.