Starch is one of the most prolific natural polymers, and is composed of amylose and amylopectin. Amylopectin molecules are much larger than amylase. Starch ethers are chemically modified from starch.

Potato starch, which is of high-purity, is the preferred amylase for building. Starch molecular weight and the degree of etherification determine the consistency and workability of the starch applied to the mortar product. The fineness of the starch determines its dissolution rate in the water.

Starch ether is one of the most cost-effective raw materials for the dry mortar industry. Its main function is adjusting the performance of the mortar in the state of fresh mixing. As a rheology modifier, it can prevent sag during mechanical construction and manual plastering, at the same time, can significantly improve the construction performance of the mortar and increase the output rate. Starch ether is effectively used in high quality tile adhesive to prevent tile slippage. It is also commonly used in self-leveling mortar and grouting material to prevent sedimentation, segregation etc.

The modification methods of starch commonly used are: carboxymethylation (CM), and hydroxyalkyl (HP) and cross-linking (CL) methods. Amylase gains rapid swelling, smooth, as well as resistance to alkali, temperature stability, high-technity and shear stability through different chemical modifications.

The particle size can change on the solubility of starch. The smaller the particle size, the faster the dissolution rate of starch is, so is in the thickening effect. Through physical modification, the applicability of starch is more broad.