Mechanical and thermal properties of silicon nitride reinforced polybenzoxazine nanocomposites

Silicon nitride (SN) nanoparticle-reinforced polybenzoxazine nanocomposites were produced with good processability at various fractions of nano-SN ranging between 0 and 30 wt% via a compression molding technique. At the maximum nano-SN loading, the DMA of the nanocomposites showed an increase of 2 GPa and 47 °C in stiffness and glass transition temperature (Tg), respectively. In addition, increasing the nano-SN fraction to 30 wt% significantly enhanced both the tensile strength and the micro-hardness of the nanocomposites. The TGA results revealed that the thermal stability of these nanocomposites was highly improved upon the addition of the reinforcing phase. The enhancements in the thermal and mechanical properties of these nanocomposites are attributed to the uniform nanoparticle dispersion and to the strong matrix-particle interactions based on the SEM and TEM results. Therefore, these nanocomposites are more suitable for high performance coating applications.