Polybenzoxazine/single-walled carbon nanotube nanocomposites stabilized through noncovalent bonding interactions

In this study we prepared a new class of pyrene-functionalized benzoxazines (Py-BZ) through reactions of phenol, paraformaldehyde, and pyren-1-amine (Py-NH2) in toluene and EtOH. We prepared Py-NH2 through catalytic reduction of 1-nitropyrene (Py-NO2), which we had synthesized through electrophilic aromatic substitution of pyrene, using HNO3 as the nitration agent. 1H and 13C nuclear magnetic resonance spectroscopy and Fourier transform infrared (FTIR) spectroscopy confirmed the chemical structure of this new monomer; differential scanning calorimetry (DSC) and FTIR spectroscopy revealed the curing behavior of the Py-BZ polymers. The presence of the pyrene-functionalized benzoxazine enhanced the solubility of single-walled carbon nanotubes (SWCNTs) in THF, leading to the formation of highly dispersible Py-BZ/SWCNT organic/inorganic hybrid complex materials. Fluorescence emission spectroscopy revealed significant π–π stacking interactions between the Py-BZ and the SWCNTs in these complexes. In addition, differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis revealed that incorporating the SWCNTs into the Py-BZ matrix significantly enhanced the thermal stability of the polymer after thermal curing.