The cellulose ether is also known the rheology modifier, i.e., an additive used to adjust the rheological properties of fresh mortar. The main functions are as follows:
(1). It enables the fresh mortar to thicken, thus prevents segregation and obtains uniform plasticizers;
(2). It has air entraining effect itself, and can also stabilize the introduced uniform and fine bubbles in the mortar.
(3). As an water-retaining agent, it helps keep moisture (free water) in the thin layer mortar, and thus the cement can have more time for hydration after the construction of mortar. The cellulose ether mainly has the above functions.
In Europe, the most commonly used cellulose ethers in the dry-mix mortar are methyl hydroxy ethyl cellulose ethers (MHEC) and hydroxypropyl methyl cellulose ethers (HPMC). Both account for an market share in dry mortars of at least 90%.