DESMODUR E 21 is an aromatic polyisocyanate prepolymer based on diphenylmethane diisocyanate (MDI). It offers medium viscosity and NCO content of 16.0 + 0.7 %. DESMODUR E 21 has good solubility and compatibility with various solvents and co-reactants. It can be used as a binder for formulating moisture-curing, one-component coatings and adhesives. DESMODUR E 21 provides excellent bonding strength and durability. When combined with suitable polyols, it yields tough yet flexible and wear-resistant coatings. These coatings exhibit high moisture and chemical resistance making them ideal for protecting various substrates against moisture, oil, fuels and other chemicals. DESMODUR E 21 is also suitable for formulating moisture-curing one-component adhesives and two-component adhesives using polyols. The adhesives offer strong adhesion and can be used to bond many common construction materials like wood, metal and plastic.