Application of Starch Ether in Cement- Based Products

Starch ethers are used in cement-based systems such as plastering, adhesives, and leveling layer to form functional surfaces both internally and externally. Plastering mortar is used to cover uneven parts of walls. They must have a strong and durable bond to the substrate. The surface of the mortar must become smooth and flat in order to give uniform absorption and good modification for subsequent treatment such as painting. In terms of rheological properties, the requirements are similar to those in the application of gypsum plaster. Although different mortars have different requirements for materials, different types of starch ethers have one property in common- endow the mortar have thixotropic rheological property to prevent the sagging and improve the pumping performance, thus facilitating the decoration and plaster. Even a very low dosage (usually less than 0.05 %) is sufficient to produce adequate rheological properties.

1. Starch ether can be used in thin decorative plastering, such as finish coating thickening, and main function is to promote the surface smoothness.

• In cement-based tile adhesive, it is important to have the properties like simple processing method, long open time, excellent anti-slip and bonding strength while applying on the wall and tile. After starch ether is added, it can increase the open time, prevent ceramic tile slipping and have very good adhesive strength with base material.

Many experiments have shown that adding starch ether and optimizing the amount of cellulose ether and redispersible polymer powder, can completely prevent ceramic tile from falling off, and the viscosity of tile adhesive basically remains unchanged. The correction time and exposure time are extended, and the formula works much better than the original formula.

Like many dry mortar products, tile adhesives have been classified according to European standards. By adding starch ether, tile adhesive has good anti-slip ability and can be improved to T level standard, exposure time extension to the E level standard.