Isonate 181 Isocyanate Dow Chemical PU - Prepolymers >> Isocyanate >> MDI based ADHESIVE ISONATE* 181 MDI prepolymer is a modified MDI compound produced by reacting high-purity diphenylmethane diisocyanate with sufficient glycol to allow easy handling down to 80°F (27°C). This medium-viscosity, supercooled liquid provides more rapid compatibility between isocyanates and polyols, which increases the effectiveness of catalysts present and usually results in a more easily controlled polymer reaction. Adhesives Modified MDI compound produced by reacting high-purity diphenylmethane diisocyanate with glycol. Possesses medium-viscosity. Provides more rapid compatibility between isocyanates and polyols, which increases the effectiveness of catalysts present and usually results in a more easily controlled polymer reaction.