Polymeric isocyanates by nontoxic routes. II. Nucleophilic displacement reaction on chloromethyl pendant groups by alkali cyanates

The environmental regulations regarding the solvent emissions have given impetus to the formulation of powder coatings and high solids coatings which require oligomeric or polymeric crosslinkers of desired functionality. We are exploring nontoxic routes for the preparation of polymeric isocyanates and isocyanate precursors. In this article, we report nucleophilic displacement of polymer-bound alkyl halides by cyanate ion as a novel route to polymeric isocyanate crosslinkers with no intermediacy of either phosgene or low molecular weight isocyanates. The effects of solvent and phase-transfer catalyst on the selectivity of the reaction are discussed. © 1992 John Wiley & Sons, Inc.