Abstract:Due to its excellent heat resistance, the silicon-containing aryacetylene (PSA) resin showed highly potential application in the aerospace field. However, the low thermal conductivity of PSA resin has limited its further development and application. In view of this, the paper aims to improve the thermal conductivity of PSA resin, so selected aluminum nitride particles (AlN) as filler to modify PSA resin. The AlN/PSA composite resins were prepared by mixing AlN particles with different particle sizes and highly heat-resistant PSA resin. The aluminate coupling agent was used to modify the surfaces of AlN particles. The modified AlN particles were mixed with PSA resin to prepare the modified AlN/PSA composite resin. The effects of AlN content, particle size, and surface modification on the thermal conductivity of cured resin were investigated. The electrical properties of cured resin were also studied. The curing process of the resin was investigated by differential scanning calorimetry (DSC), and the modification effect of the coupling agent was characterized by infrared spectroscopy (FT-IR). The thermal properties of cured AlN/PSA composite resins were investigated by thermogravimetric analysis (TG) and dynamic thermo-mechanical analysis (DMA). Scanning electron microscopy (SEM) were used to observe the cross-sectional morphology of cured resin. X-ray energy dispersive spectroscopy (EDS) analysis was used to observe the elemental distribution of the fracture surface. Results show that when AlN particle size, mass fraction of coupling agent and volume fraction of AlN are 45 μm, 3%, and 24%, respectively, the thermal conductivity of the cured AlN/PSA composite resin achieved 2.36 W/( m·K). At the same time, the heat resistance of the cured composite resin is improved. The cured composite resin has good dielectric and insulating properties, in which the dielectric constant is lower than 3.8 and the electrical resistivity is higher than 108 Ω·cm in the range of 10 Hz to 1 MHz.