Vegetable oil-based, coumarin-containing antibacterial thermosets with improved thermal stability via copper-free thermal azide-alkyne click polymerization

In recent years, the preparation of thermoset materials based on renewable sources has received peculiar attention. In this work, we prepared vegetable oil based antibacterial thermosets via thermal azide−alkyne cycloaddition reactions. Dimer diamine was propargylated and mixed with azidated trimethylolpropane triglycidyl ether and castor oil bearing azide and phosphorous groups. Two different propargyl functionalized coumarins were also incorporated into the vegetable oil based formulations. All synthesized monomers were characterized by Fourier-transform infrared (FTIR) and Nuclear magnetic resonance (NMR) spectroscopy. Mechanical, thermal and antibacterial properties of the obtained thermosets were also determined. The thermosets behaved as elastomers and displayed elongation at break values between 39% and 82%. The phosphorylated castor oil derivative improved the thermal properties and char yields as high as 13.83% at 750 °C were observed under nitrogen atmosphere. Coumarin-containing thermosets were found to have antibacterial activity against both gram-positive and gram-negative bacteria. • Propargylated dimer diamine and two novel coumarins were synthesized. • Castor oil bearing azide and phosphorous groups was prepared. • Thermosets were developed with these monomers. • Thermal azide−alkyne cycloaddition was utilized. • Thermosets displayed antibacterial properties and improved thermal stability.