Bio-polyurethanes from Sapium sebiferum oil reinforced with carbon nanotubes: synthesis, characterization and properties

The physicochemical properties and fatty acid profile of natural Sapium sebiferum oil (SSO) were analyzed and found to have a high iodine value of 186.8 g/100 g. Then, a novel SSO-based polyurethane (PU) was successfully synthesized via an in situ polymerization method, and multi-walled carbon nanotubes (CNTs) were modified by an acid mixture and ethylenediamine (EDA) to further reinforce the PU matrix. The microstructure and the properties of the functionalized CNTs and the PU/CNT composites were characterized by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results showed that amino-functionalized CNTs could homogeneously disperse in the PU matrix and significantly improved the thermal and mechanical properties of the composite. Compared with pure PU, the glass transition temperature and initial decomposition temperature of the PU matrix with amino-functionalized CNTs were respectively enhanced by 17.1 and 32.5 °C. Meanwhile, 295% improvement in the tensile strength, 111.3% enhancement in the Young's modulus and 22.4% increment in the elongation at break of the composite were observed. The properties of the PU/CNT composites indicate the great potential applications of SSO in polymer materials.