Preparation and properties of high-performance polyethersulfone composites reinforced by modified silicon nitride

Si3N4 fillers were added to polyethersulfone (PES) using the solution mixing and ball-mill mixing methods to increase the thermal conductivity. 3-Aminpropyltriethoxysilane was used as a coupling agent for the surface modification of the Si3N4 particles. The morphology, thermal stability, mechanical properties, and thermal conductivity of the Si3N4/PES composites were then studied in detail. The dispersion of the Si3N4 particles into the matrix resin was higher in ball-mill mixing than in solution mixing. As the Si3N4 content increased, the coefficient of thermal expansion of the composites gradually decreased, whereas the Vickers hardness and thermal conductivity increased. At 19 vol.% Si3N4, the thermal conductivities of the composites via ball-mill mixing and solution mixing reached 0.677 and 0.7 W/m.k, respectively.