FORMamides as Isocyanates surrogates for CAtalytic polyurethanes synthesis – FORMICA

FORMICA relies on an interdisciplinary approach that closely combines molecular catalysis, DFT calculations and macromolecular chemistry. It proposes an unprecedented polymerization pathway using di-N-substituted FormAmides (di-NFA, H(O)C-N(R)----(R)-NC(O)H) as di-isocyanate surrogates for the synthesis of PUs via Dehydrogenative Coupling (DC: RNC(O)-H + HOR’ -> RNC(O)-OR’). Compared to isocyanates, NFAs appear as attractive precursors, since easily prepared from aryl-/alkyl-amines and CO2, an abundant, cheap and readily available raw material. The main challenge is the design of polymerization catalysts capable of promoting DC with very high conversions at stoichiometry (NCHO/OH ratio = 1:1) to afford high molar masses PUs. In this project, the rational design of catalytic systems based on copper (oxidative pathway) and manganese (acceptorless pathway) is proposed. To achieve this, our methodology uses two major key levers that are ligands engineering and mechanistic studies. The latter will involve a dual experimental-computational approach aiming at rationalizing ligand effects and in terms, guiding their design. The non-isocyanate polyurethanes (NIPUs) obtained will be fully characterized structurally and their mechanical properties will be determined.
To sum up, the alternative route to NIPUs proposed in FORMICA is expected to combine several assets regarding the nature of the precursors (N-substituted FormAmides = CO2-derived synthon versus isocyanates = phosgene-derived synthon), the low environmental impact of the side products (alcohols, hydrogen), and the use of catalysts based on abundant non-critical metals (Cu, Mn).