Papi 901 Isocyanate Dow Chemical PU - Isocyanates >> MDI, diphenylmethane diisocyanate >> Polymeric MDI ADHESIVE SEALANT PAPI* 901 polymeric MDI is a polymethylene polyphenylisocyanate that contains MDI. This product has a high functionality and a high viscosity resulting in highly rigid foams. This product is designed for uses where high viscosity is required for processing polyisocyanurate foams. Adhesives Sealants Polymethylene polyphenylisocyanate that contains MDI. Possesses a high functionality and a high viscosity resulting in highly rigid foams. Used where high viscosity is required for processing polyisocyanurate foams.