Cellulose ether is a group of chemical compounds derived from cellulose, the most abundant organic polymer on Earth, found in plant cell walls. Cellulose ethers are modified by introducing ether groups (-OCH3, -OH, -COOH) into the cellulose structure, which alters its properties and makes it soluble in water. https://www.kimachemical.com/cellulose-ether-3.html