Enhanced Thermal Properties of Epoxy Composites by Using Hyperbranched Aromatic Polyamide Grafted Silicon Carbide Whiskers

In this report, we demonstrate that the thermal conductivity, glass transition temperature, thermal stability and dynamical mechanical properties of epoxy composites could all be improved by incorporating hyperbranched aromatic polyamide grafted silicon carbide (SiC-HBP) whiskers, using a solution method. The morphology and thermal properties of these newly modified epoxy composites were systematically analyzed and studied. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and thermal gravimetric analyses (TGA) proved hyperbranched aromatic polyamide grafted SiC whiskers were successfully prepared by solution polymerization. The thermal conductivity of epoxy composite with 30 wt% of SiC-HBP had 2-fold improvement, compared to that of the neat epoxy. Besides, the glass transition temperatures (T-g) and dynamical mechanical properties of the epoxy composites were also raised by the addition of SiC-HBP, which indicates strong interfacial adhesion between SiC-HBP and the epoxy matrix. Most importantly, the incorporation of SiC-HBP in the epoxy matrix could effectively improve the thermal stability of the epoxy composites, according to our thermogravimetric analysis (TGA).