Toward Fully Renewable Rigid Polyurethane Foams with Aliphatic Diisocyanates

Fully renewable materials will be a key component of sustainable plastic development and management, and the industrial reliance on petroleum-derived monomers, including aromatic diisocyanates used in polyurethanes (PUs), must be minimized to meet sustainability and production goals. To date, aliphatic diisocyanates have shown great promise as renewable monomers, and scalable production is imminent. This work demonstrates a systematic study and application of aliphatic diisocyanates for the preparation of rigid PU foams. Aliphatic 1,6-hexamethylene diisocyanate (6-HDI) was incorporated with multifunctional renewable polyols and cross-linkers to produce rigid polyurethane-polyisocyanurate foams with high renewable carbon content. Morphological, thermal, and mechanical analyses of these novel foams indicated similar properties and performance to those of commercial rigid foams. The described synthesis of rigid foams without utilization of aromatic diisocyanates broadens the scope of rigid foam formulations possible and serves to advance the understanding of renewable foam and material development.