Biobased Polyurethane Films Based on Andiroba ( <scp> <i>Carapa guianensis</i> </scp> ) and Buriti ( <scp> <i>Mauritia flexuosa</i> </scp> ) Oil Polyols

ABSTRACT This study reports the synthesis of new bio‐based polyurethane (PU) films using polyols derived from enzymatic glycerolysis of andiroba ( Carapa guianensis ) and buriti ( Mauritia flexuosa ) oils. The glycerolysis process yielded polyols rich in monoacylglycerols (70–78 mol%) with hydroxyl values of 388–397 mg KOH g −1 , while preserving phenolic compounds and, in the case of buriti oil, carotenoid‐related molecules. Those polyols were blended with PEG 400 to produce solvent‐cast PU films, with vegetable polyol contents ranging from 5 to 100% of the total polyol mixture. Urethane formation was confirmed by FTIR, and mechanical testing revealed that formulations containing 50% vegetable polyol exhibited the best performance, with tensile strength reaching up to 15 MPa. UV–Vis analysis demonstrated the presence of carotenoid‐related absorption bands in buriti‐based PU films, indicating successful incorporation of bioactive compounds into the polymer matrix. To the best of our knowledge, this is the first report of buriti oil‐derived polyols used as reactive monomers for PU film formation. These results demonstrate the feasibility of producing PU films from Amazonian vegetable oils via an enzymatic route while preserving intrinsic bioactive functionality, contributing to the development of sustainable polymeric materials.