The advanges of HPMC & MHEC in dry mix mortar products
November 22nd 2024
Hydroxypropyl methylcellulose (HPMC)
Hydroxypropyl methyl cellulose (HPMC) product characteristics
1. Properties: This product is a white powder, and is odorless, tasteless and non-toxic.
2. Water retention: As this product can only attach water several times heavier than itself, it can maintain high water retention in mortar, gypsum, paint and other products.
3. This product can be dissolved in cold water to form a transparent viscous solution.
4. Dissolution in organic solvents: Because it contains a certain amount of hydrophobic genes, this product can be dissolved in some organic solvents, as well as mixed solvents of water and organic matter.
5. Salt resistance: Because this product is a non-ionic and non-polyelectrolyte, it is relatively stable in aqueous solutions of metal salts or organic electrolytes. In the case of too much electrolyte, it may cause gelation or precipitation.
6. Surface activity: The aqueous solution of this product has surface activity and functions as a protective colloid, emulsifier and dispersant.
7. Thermal gelation: When heated to a certain temperature, this product will become an opaque solution to the aqueous solution due to gel or precipitation. But it changed into the original solution state after gradually cooling. The temperature at which condensation and precipitation occur depends on the type of product, the concentration of the solution and the heating rate.
8. Low ash content: Because this product has thermal gel properties, it is washed with hot water during the preparation process to achieve the purpose of refining, so its ash content is very low.
9, PH value stability: The viscosity of the aqueous solution of this product is almost not affected by acid and alkali, and the solution is stable in the range of PH3.0-11.0.
10. Shape retention: Compared with other aqueous polymers, the aqueous solution of this product has special viscoelastic properties. It has the ability to maintain and improve the shape of extruded ceramic products.
11. Lubricity: Adding this product can reduce the coefficient of friction and improve the lubricity of extruded ceramic products and cement products.
12. Film-forming properties: This product can produce strong, flexible, transparent flakes with good oil and grease resistance.
13, Suspension: It can prevent solid particles from settling, thus inhibiting the formation of precipitates.
14. Adhesiveness: Used as an adhesive for pigments, tobacco products, and paper products, with excellent functions.
The properties of hydroxypropyl methylcellulose
Hydroxypropyl methyl cellulose is a non-ionic cellulose ether, white powder in appearance, odorless and tasteless, soluble in water and most polar organic solvents and appropriate ratio of ethanol/water, propanol/water, dichloroethane Alkanes, etc., are insoluble in absolute ethanol, and swell into a clear or slightly turbid colloidal solution in cold water. The aqueous solution has surface activity, high transparency and stable performance. HPMC has thermal gel properties. The product solution forms a gel and precipitates after heating, and then dissolves after cooling. The gel temperature of products of different specifications is different. The solubility changes with the viscosity. The lower the viscosity, the greater the solubility. The properties of different specifications of HPMC have certain differences. The dissolution of HPMC in water is not affected by the pH value. HPMC has the characteristics of thickening ability, salt excretion, PH stability, water retention, dimensional stability, excellent film-forming properties and wide range of enzyme resistance, dispersibility and adhesion.
── Stability
Used as a film-forming agent, thickener, emulsifier and stabilizer in latex coatings and water-soluble resin coatings, so that the coating film has good wear resistance, leveling and adhesion, and improves surface tension and PH stability , And compatibility with metal color materials, in water-based paint, this product has excellent storage stability, maintains a uniform viscosity, makes the pigments evenly dispersed, and is basically not affected by the pH value.
── Water retention
The main function of cellulose in putty is water retention, adhesion, lubrication and so on. It has high water retention, surface wiping performance and improved uniformity. Avoid the phenomenon of skin peeling, improve shrinkage resistance and crack resistance, improve sag resistance, and it will be more comfortable after scraping, saving effort, etc., which improves work efficiency.
──Adhesion
Bonding mortar and plastering mortar for thermal insulation mortar system: Cellulose in this material mainly plays the role of bonding, retaining water and increasing strength. It has improved construction, high water retention, and anti-hanging ability. Improve anti-sagging ability, improve shrinkage resistance and crack resistance, improve bonding strength, improve work efficiency, etc.
Tags:
