The surface active (surfactant) properties of Tylose^® are due to the chemical structure of cellulose ether molecules and especially due to the simultaneous existence of hydrophilic and hydrophobic groups. The surface activity of cellulose ether molecules increases with an increasing number of hydrophobic groups. Thus, in aqueous solutions, particularly Tylose MH and Tylose MO grades are surface active, while this effect is less pronounced with Tylose H grades and even less with ionic cellulose ethers. Tylose MH grades lower the surface tension of water (72 mN/m) by about 20 mN/m, Tylose H grades by about 10 mN/m and carboxymethyl cellulose only by about 2 mN/m.

A special effect of the surface activity of methyl cellulose is its distinct ability to foam. The stabilization of air voids in mineral mortar systems is often desirable and guarantees a “smooth application”.