Non-isocyanate Polyurethanes for Thermoplastics and Foams: Opportunities for Green Chemistry and Sustainability

The interest for monomers with reduced toxicity and broader applications is driven in part by the green chemistry revolution. As synthetic chemistries continue to develop, the desire to infuse sustainability into research catalyzes the development of new pathways for polymer synthesis. One such example is the utilization of carbonyldiimidazole (CDI) to drive the isocyanate-free synthesis of polyurethane foams and thermoplastics in a solvent-free, catalyst-free process. The versatile reactivity of CDI enables new families of bis-carbonylimidazole (BCI) monomers, which readily react with amines to form linear and crosslinked polyurethanes. This new CDI chemistry presents the potential for new structure-property relationships for high performance applications and safer engineering platforms for manufacturing while simultaneously implementing green chemistry. The elimination of petroleum-derived solvent, while simultaneously increasing the versatility of the final polyurethane harmonizes BCI monomers with green chemistry. Current research focuses on understanding the fundamental structure-property relationships in the isocyanate-free CDI system with the goal of creating a more circular use for polyurethanes globally.