Starch ether is a general term for a class of modified starches containing ether bonds in the molecule, also known as etherified starch, which is widely used in medicine, food, textile, papermaking, daily chemical, petroleum and other industries. Today we mainly explain the role of starch ether in mortar:
1) Thicken the mortar, increase the anti-sagging, anti-sagging and rheological properties of the mortar
For example, in the construction of tile adhesive, putty, and plastering mortar, especially now that mechanical spraying requires high fluidity, such as in gypsum-based mortar, it is especially important (machine-sprayed gypsum requires high fluidity but will cause serious sagging, starch Ether can make up for this deficiency). That is, when an external force is applied, the viscosity decreases, enhancing the workability and pumpability, and when the external force is withdrawn, the viscosity increases, improving the sagging resistance. For the current trend of increasing tile area, adding starch ether can improve the slip resistance of tile adhesive.
2) Extended opening hours
For tile adhesives, it can meet the requirements of special tile adhesives (Class E, 20min extended to 30min to reach 0.5MPa) that extend the opening time. Starch ether can make the surface of gypsum base and cement mortar smooth, easy to apply, and has good decorative effect. It is very meaningful for plastering mortar and thin layer decorative mortar such as putty.
1. Starch ether can effectively improve the anti-sag and anti-slip properties of mortar
Cellulose ether usually can only improve the viscosity and water retention of the system but cannot improve the anti-sagging and anti-slip properties.
2. Thickening and viscosity
Generally, the viscosity of cellulose ether is about tens of thousands, while the viscosity of starch ether is several hundred to several thousand, but this does not mean that the thickening property of starch ether to mortar is not as good as that of cellulose ether, and the thickening mechanism of the two is different.
3. Anti-slip performance
Compared with cellulose ethers, starch ethers can significantly increase the initial yield value of tile adhesives, thereby improving their anti-slip properties.
4. Air-entraining
Cellulose ether has a strong air-entraining property, while starch ether has no air-entraining property.
Post time: Apr-04-2023