Graphene in Bio-derived Polyurethane for Improved Mechanical Properties

Polyurethane based polymers have a wide range of application due to their versatility. And to mention a few, they can be manipulated into foams in car seats, medical devices and lubricants. Until recently, polyols, which play a vital role in the properties of polyurethane were petroleum based. However, due to their fast depletion and the earnest need to protect the environment, researchers are more intrigued about using green and costefficient alternatives. Scientists have found bio-based polyols from sources like vegetable oils and limonene to produce polyurethanes with high quality properties hence, the gradual expansion in that research area. In this work, sunflower oil is converted into a polyol using an epoxidation reaction followed by ring opening with methanol. The polyol is further used in the synthesis of a polyurethane composite in an easy one step reaction with isocyanate. To improve the mechanical properties of the bio-based polyurethane composite, graphene was introduced in increasing percent concentrations. The dispersion of the graphene as well as the effects of the polyol was studied. In addition, TGA, and elasticity among the many others were used to test the effects of graphene on the properties of the materials. It was observed that the elastic modulus and tensile strength increased to over 450 MPa and 47 MPa respectively. TGA results also showed a high thermal stability of our synthesized materials. This experiment established a fast and facile method for the production of the biobased polyurethane composites that had improved mechanical properties with the addition of graphene