Synthesis and characterization of polyurethane/zinc oxide nanocomposites with improved thermal and mechanical properties

The study presents the synthesis of polyurethane/zinc oxide (PU/ZnO) nanocomposites from polyethylene glycol (PEG, MW = 8000) and toluene 2,4 diisocyanate (TDI) within a temperature range of 40 to 60 °C. Structural confirmation and particle size of ZnO were carried out through SEM, FTIR spectroscopy and XRD. Structural insight through XRD presented hexagonal crystals with an average diameter of 33.8 nm. While thermal stability was investigated through thermogravimetric analysis (TGA). The PU/ZnO nanocomposite films were prepared in a Teflon petri dish using different percentages of ZnO; 2%, 4%, 6%, 8%, and 10% in stoichiometric amounts. Functional groups analysis was carried out through FTIR, and it showed the addition of ZnO within the polymer matrix. SEM analysis demonstrated that nanoparticles were homogeneously dispersed all over the polymer surface, responsible for the improvement of inherent properties. TGA study confirmed that homogeneously dispersed nanoparticles improved the thermal stability of polyurethane. The results of TGA graphs showed that the thermal stability of PU/ZnO nanocomposites was increased as the concentration of incorporated ZnO nanoparticles increased as compared to pure polyurethane. Mechanical properties of the nanocomposites were also improved in terms of maximum strain and stress at break, young’s modulus and toughness owed to homogenous dispersion and better material properties.