Polymeric Methylene Diphenyldiisocyanate (pMDI) is a brown mixture of monomeric (2-ring) and polyaromatic 3-ring and higher species) Methylene Diphenyldiisocyanates, which is liquid at room temperature. A higher pMDI viscosity indicates a lower content of monomeric and a higher content of polyaromatic components; that is, as pMDI viscosity increases, so does isocyanate functionality. BASF offers a range of pMDIs with different functionality and reactivity. PMDI is mainly used for the production of rigid foam, pMDI grades are also used as a binder in the wood-working industry. In combination with mMDI grades, polymeric MDI is also used to produce various types of flexible foam and CASE applications.