(646f) Non-Isocyanate Synthesis of Lignin-Based Polyurethane Foam

Polyurethanes (PU) are the fifth most widely used polymeric materials in modern life, finding diverse applications in insulation, construction, furniture, and medical devices. However, conventionally, PU is produced from petroleum-based polyols and highly toxic diisocyanates. To achieve sustainable and green production of the PU foams, a non-isocyanate synthesis using lignin derived from biomass is developed. Lignin was first extracted via co-solvent enhanced fractionation (CELF) process, then further fractionated and characterized with NMR and GPC. The fractionated lignin was epoxidized and converted to carbonated lignin through a carbon-negative process. The non-isocyanate synthesis of PU was readily conducted by reacting carbonated lignin with diamines. A novel one-step lignin epoxidation process was developed, and the impact of lignin structure on epoxidation was investigated, yielding insights into the selection of starting materials, with the aim of achieving high-performance, eco-friendly, and cost-competitive biobased PU insulating foams.