One‐Pot Two‐Step Synthesis of Hydroxymethylated Unsaturated VHOSO and Its Application to the Synthesis of Biobased Polyurethanes

Abstract A one‐pot two‐step procedure is developed to catalytically convert very high‐oleic sunflower oil (VHOSO) into hydroxymethylated unsaturated derivatives featuring both primary alcohols and carbon–carbon double bonds. The degree of functionalization in alcohols and C═C double bonds can be accurately controlled affording low and high substituted hydroxymethylated VHOSO. The key point to achieve such control is to partly hydroformylate the C═C bonds at 80 °C and to subsequently reduce the reaction temperature to 20 °C to selectively reduce the aldehydes, while keeping a high CO/H2 pressure. Step‐growth polymerization of highly substituted hydroxymethylated VHOSO with cyclohexyl isocyanate or 4,4ʹ‐methylenebis(cyclohexyl isocyanate) furnishes biobased polyurethanes with improved thermal stability compared to similar polyurethanes synthesized from castor oil. Practical Applications: This study highlights the implementation of triglycerides featuring both C═C double bonds and hydroxymethyl groups. The synthesis proceeds through a one‐pot two‐steps procedure that consists of a hydroformylation reaction at 80 °C followed by a hydrogenation reaction carried out at room temperature. This simple synthetic procedure is of major interest in a context of an industrial–environmental approach. The high reactivity of the obtained primary alcohols allows the synthesis of bio‐PUs, displaying untouched C═C double bonds, which could be further functionalized. This finding is of importance as the obtained bio‐PUs can be used in many industrial areas such as foams, elastomers, thermoplastics, thermosets, adhesives, coatings, sealants and fibers.