Methylene diphenyl diisocyanates (MDIs) are essential building blocks in the production of polyurethanes, urethane-prepolymers, and polyisocyanurate polymers in many industries. Because of their reactivity and versatility of combining with an wide array of curatives and chain extenders, MDIs are used in countless diverse applications. End-uses for these quite versatile diisocyanates include foam products, cast elastomers, thermoplastic polyurethanes (TPUs), fibers, and CASE (coatings, adhesives, sealants & elastomers) products. MDIs are the most-produced diisocyanate on a global basis.