High performance aliphatic polyurea films reinforced using nonfunctionalized multiwalled carbon nanotubes

摘要

Polyurea nanocomposites appear to be a recent advanced elastomer with high robustness. This study shows that without chemical surface functionalism, multiwalled carbon nanotubes (MWCNTs) can significantly increase the tensile strength of aliphatic polyurea nanocomposites which are cured at room temperature. This is achieved via ultrasonic dispersion techniques which prevent agglomeration and the role of MWCNTs as physical crosslink sites, encouraging the formation of hydrogen bonds, thus entangling the polymer chains in the polyurea matrix and restricting chain movement. The incorporation of MWCNT drastically increases the tensile strength of the nanocomposite by 1000%, from 2.16 +/- 0.24 MPa to 21.7 +/- 4.4 MPa. The thermal and chemical properties of samples are investigated using dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and acetone swelling tests. In this study, we showed that polyurea films reinforced with MWCNTs have high swelling resistance compared to the pure polyurea films. Aliphatic polyurea is also known to have high UV stability. The tensile properties achieved by the nanocomposite in this study are comparable to the aliphatic and aromatic polyurea products in the market and can make these films suitable products for rolling and coating applications.