Preparation of hyperbranched aromatic polyamide grafted nanoparticles for thermal properties reinforcement of epoxy composites

Epoxy nanocomposites with hyperbranched aromatic polyamide grafted alumina (Al2O3) nanoparticles as inclusions were prepared and their thermal properties were studied. The Al2O3 nanoparticles were firstly treated with a silane coupling agent to introduce amine groups, then grafting of the hyperbranched aromatic polyamide started from the modified surface. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR) analysis proved hyperbranched aromatic polyamide grafted Al2O3 nanoparticles were successfully prepared by solution polymerization. Transmission electron microscopy (TEM) showed that there was a thin polymer layer on the Al2O3 nanoparticles surface, which contributes to the uniform dispersion of Al2O3 nanoparticles in epoxy matrix and the improvement of the interfacial interaction between Al2O3 nanoparticles and epoxy matrix. Thus the glass transition temperature, thermal stability, thermal conductivity and thermomechanical properties of nanocomposites were enhanced.