Reactivity and kinetics of HDI-iminooxadiazinedione: Application to polyurethane synthesis

For many years, intensive research has been carried out for the synthesis of polyurethanes by reaction between diisocyanates and various alcohols, water or amines. However, these reactions present one major drawback: the harmfulness of diisocyanates monomers for human health and environment. Therefore industries developed different routes to avoid the use of diisocyanates. Some of these routes involve oligomers of isocyanates such as isocyanurates (trimers of diisocyanates) which present a low harmfulness. The HDI-iminooxadiazinedione (HDIOD) isocyanate is a new isocyanate trimer recently developed by industry. The main interest of such monomer seems to be its reactivity compared to classical isocyanurates. Consequently, in this study, we compared the reactivity and the kinetic of HDI-isocyanurate (HDII) the most used isocyanurate, and HDIOD. Firstly, after a structural study, we compared the properties of the polymers obtained. Then, we monitored the reactions of isocyanurates with different alcohols by H-1-INMR to determine their kinetics rate constants. Finally, we proposed a mechanism which could explain the difference of reactivity between these monomers.