Flexible,hard, and tough biobased polyurethane thermosets from renewable materials: glycerol and 10-undecenoic acid

The main theme of this work is to develop 100% biobased low viscous polyols from renewable resources. An epoxide compound (UA-GLY-E) was synthesized through esterification of glycerol and 10-undecenoic acid preceded by peroxidation. For the first time, UA-GLY-E was utilized as a building block in the generation of low viscous polyols and polyurethanes therefrom. The biobased polyols were synthesized by epoxide ring opening of UA-GLY-E with different nucleophiles, namely glycerol, water, and methanol. The advantage of these biobased polyols is their low viscosity and at the same time high functionality. These biobased polyols were further converted into poly(urethane–urea) coatings by reacting with methylene diphenyl diisocyanate. The impact of peripheral structural change in the polyols on the properties of polyols and their polyurethane coatings was studied. Flexible, hard, and tough thermosets have been prepared successfully from the same epoxy compound by altering the peripheral moiety in the polyol structure. Biobased polyurethanes prepared from glycerol and water-based polyols have shown better crosslinking density over the methanol-based polyol. Moreover, these biobased polyurethane films have shown good thermal stability, mechanical strength, and chemical resistance as well.