Enhanced aminolysis of cyclic carbonates by β-hydroxylamines for the production of fully biobased polyhydroxyurethanes

The aminolysis of five-membered cyclic carbonates, which results in polyhydroxyurethanes (PHUs), is one of the most promising synthetic pathways to achieve isocyanate-free polyurethanes (NIPUs), one of the main industrial challenges over the coming years. This study highlights the higher reactivity of beta-hydroxylamines toward cyclic carbonates compared to classical alkylamines through the determination of their reaction rate constants. The key role of the beta-OH substituent in the aminolysis was revealed by DFT investigation. Polyfunctional alkylamine and beta-hydroxyamine were then used for the synthesis of fully biobased PHU thermosets. The higher reactivity of beta-hydroxylamines was confirmed by the gelation time gap between the two formulations studied. After curing, the thermal and thermo-mechanical properties of the thermosets were compared.

Automated summary

This study highlights the higher reactivity of beta-hydroxylamines towards cyclic carbonates compared to classical alkylamines through determination of their reaction rate constants. The key role of the beta-OH substituent in the aminolysis was revealed by DFT investigation. The higher reactivity of beta-hydroxylamines was further confirmed by the gelation time gap between the two formulations studied, leading to the synthesis of fully biobased PHU thermosets.