Synthesis and characterization of vegetable oil based polyurethanes with tunable thermomechanical performance

The replacement of petroleum based polymers with the environmental-friendly counterparts derived from renewable resource has received much attention due to the growing concern toward the depletion of the world crude oil stock and environmental problem. In this study, a series of biobased polyurethanes were successfully prepared from polyols obtained by thiol-ene reaction of different plant oils (olive, rice bran, grape seed and linseed oils). Their properties were characterized by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile test. Their thermomechanical and mechanical properties were compared and discussed to reveal the structure-property relationship. The results show that as the hydroxyl values of the polyols increase, T(g)s and tensile strengths of the corresponding polyurethanes increase linearly while the thermal stability decrease. Furthermore, polyurethane from linseed oil had the highest T-g of 65.2 degrees C and tensile strength of 50.7 MPa. The resulting polyurethane films with tunable thermomechanical performance are promising to find application in coatings, leather, adhesive and so on.