Effect of the biobased polyols chemical structure on high performance thermoset polyurethane properties

The sustainability of the polymeric materials has become a fundamental challenge; therefore, the development of new biobased formulations has gained increasing interest. Thermoset polyurethanes (PURs) present high performance and are a competitive solution for structural composites. However, polyols used in the PUR synthesis are typically from petrochemical origin. Nowdays, a broad range of biobased polyols is available in the market, but there is not yet a specific formulation for high performance PURs composites. The aim of this work was to study the effect of biobased polyols' characteristics in the PUR processing and final properties. In addition, biobased polyol features to synthesize BIO-PURs suitable for structural applications were stablished. The viscosity and reactivity were studied by means of rheology and differential scanning calorimetry (DSC). Thermal and mechanical properties were studied through thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and flexural tests. The results obtained demonstrated the dramatic influence of polyols’ nature on BIO-PUR/PUR properties and their effect on the crosslink density. It was observed that using a high functionality and high hydroxyl index biobased polyol, it was possible to synthesize high performance BIO-PUR suitable for structural composites.We gratefully acknowledge the Basque Government for the financial support through the ELKARTEK 2021 (Project NEOMAT KK-2021/00059) program and in the frame of Grupos Consolidados (IT-1690-22). The authors also acknowledge the University of the Basque Country (UPV/EHU) in the frame of GIU18/216 Research Group and the Macrobehavior-Mesostructure-Nanotechnology SGIker unit