PEP Review 77-2-5
Polymeric Polyisocyanates (PMPPI) or Polymeric MDI by Carbonylation Process
Published: May 1979
A new process for making polymeric polyisocyanate proceeds from nitrobenzene via carbonylation with an alcohol to a urethane. The urethane is condensed with formaldehyde to produce a diurethane and its polymeric forms, which are then decomposed to form the polyisocyanate.
Our preliminary evaluation found that this process may be economically viable. The isomer distribuition of the product would be different from the present commercial PMPPI.