A fully bio-based monomer derived from undecylenic acid, glycerol, and CO2 useful for the synthesis of polyhydroxyurethanes

Undecylenic acid, glycerol, and CO2 were used as building blocks for obtaining a fully bio-based carbonated monomer, useful for polyurethanes. The functionality of the monomer was close to 3 cyclic carbonates/mol, located in terminal positions. In a first stage, a synthetic triglyceride was obtained with 99% selectivity by esterification of glycerol and undecylenic acid at 160 degrees C. The triglyceride was then epoxidized using H2O2 and Amberlyst 15 or Amberlite IR-120 acidic exchange resins at 57 degrees C. The selectivity to epoxide was kept constant at 98% using Amberlite IR-120. Terminal cyclic carbonates were then inserted through epoxide moieties under mild conditions by the chemical fixation of CO2 at 80 degrees C and 6 MPa in 6 h. A complete conversion was obtained in 6 h reaction while the selectivity to carbonate groups was near to 99% during all the reaction time. An elastomeric polyhydroxyurethane was obtained by aminolysis of the carbonated monomer with ethylenediamine at 70 degrees C, affording a Young's modulus of 22.6 MPa and T-g of -15.2 degrees C. The material showed a good thermal stability below 240 degrees C.

Automated summary

A fully bio-based carbonated monomer was synthesized using undecylenic acid, glycerol, and CO2 as building blocks, which was then used to obtain an elastomeric polyhydroxyurethane. The synthesis involved several steps with high selectivity, resulting in a material with good mechanical properties and thermal stability.