Polymethylene polyphenylene isocyanate

Polymethylene polyphenylene isocyanate (CAS 9016-87-9), commercially known as Polymeric MDI, is a dark brown liquid isocyanate used as a reactive building block in polyurethane synthesis.

It functions as a crosslinker and chain extender, reacting with polyols to form rigid or semi-rigid polymer networks across a broad range of industrial applications.

In construction and insulation, Polymeric MDI is the primary isocyanate component in rigid polyurethane and polyisocyanurate foam systems used for panels, spray foam, and pipe insulation.

Automotive and industrial manufacturers use it to produce structural reaction injection molded parts, seat foam, and under-hood components requiring dimensional stability.

In adhesives and sealants, it delivers strong substrate bonding across wood, metal, and composite materials, particularly in wood composite panels such as OSB and LVL.

Coatings formulators use it to build moisture-cure and two-component systems for flooring, protective coatings, and elastomeric membranes for various industrial surfaces.

Polymeric MDI is supplied as a liquid in bulk tankers, ISO containers, and drum quantities. Standard commercial grades vary by NCO content and viscosity for rigid foam applications.

Technical grade is the predominant market form; food-contact or pharmaceutical grades are not applicable for this product as it is intended for industrial use.