[C6H7O2(OH)3–x(OC2H5)x]n, the ethyl ether of cellulose.
Produced by the reaction of alkaline cellulose with ethyl chloride, ethyl cellulose takes the form of an odorless, tasteless, white powder with a density of 1.09–1.17 g/cm3. Readily soluble in many organic solvents, it is resistant to the action of water, alkaline solutions, and dilute mineral acids up to a temperature of approximately 80°C, but it breaks down in concentrated acids. Ethyl cellulose is compatible with other cellulose ethers, mineral oils, vegetable oils, most plasticizers, and many natural and synthetic resins. It is physiologically harmless.
Ethyl cellulose is thermoplastic, with a softening point of 140°–170°C and a melting point of 160°–210°C; it decomposes at temperatures above 200°C. Since the melts of ethyl cellulose are rapidly oxidized in the air, stabilizers—such as derivatives of aromatic alcohols or amines—must be added.
Products made from ethyl cellulose include automobile parts and the cases of radios; all the manufacturing methods employed with thermoplastics can be used with ethyl cellulose (seePLASTICS). Ethyl cellulose is also used to produce lacquers (see) and films (seePOLYMER FILMS). Articles made from ethyl cellulose are strong, having a Young’s modulus of 2.35 × 103 meganewtons per m2; they are resistant to frost and chemicals, and they have a low thermal conductivity and rate of combustion.