Allophanate formation in oligodienediol-aromatic diisocyanate system

The kinetics and mechanism of allophanate formation were studied. It was found that the reactivity of oligodieneurethanes of various molecular masses is determined by the ratio between the different forms of associated end groups. Using model compounds as an example, it was shown that the ionization of oligodieneurethane to an enolic anion is the first stage of allophanate formation. The parameters of molecular mass distribution of the compounds formed in the course of reaction were determined. The conditions that eliminate the occurrence of the side reaction were identified.