Catalyzed non-isocyanate polyurethane (NIPU) coatings from bio-based poly(cyclic carbonates)

Formulations of bio-based poly(cyclic carbonates) and amines using cooperative catalysis were studied to produce non-isocyanate polyurethanes (NIPUs). Concerns on the use of isocyanates as starting materials for polyurethanes (PUs) have risen due to their effects on human health after exposure and also because their synthesis involves the use of phosgene. Polyurethanes are highly versatile materials used in widespread industries such as automotive, building, construction, and packaging. They have also been used as flexible and rigid foams, adhesives, coatings, thermoplastic, or thermoset materials. Traditionally, PUs are synthesized from polyols and polyisocyanates. In order to circumvent the concerns, much research has been devoted to exploring alternative approaches to the synthesis of PUs. NIPU synthesis using cyclic carbonates and amines has gained popularity as one of the new approaches. In this study, novel bio-based resins were synthesized by converting epoxidized sucrose soyate into carbonated sucrose soyate (CSS) under supercritical conditions. Initial studies have shown promise in systems where CSS is crosslinked with multifunctional amines generating coatings with good solvent resistance. This work focused on studying the effect of catalysts and developing formulations of bio-based non-isocyanate polyurethane coatings.