Ball milling was used to decrease the particle size of boron nitride (BN) nanoplates and to form more silylated functionalization of their surface. Such functionalized BN nanoplates enhanced their homogeneous dispersion in polyimide (PI) matrix. Thermal conductivities, thermal stabilities, and dielectric properties were characterized to investigate the particular effects on the performance of PI-based composites with functionalized BN nanoplates. When the concentration of functionalized BN nanoplates increased to 50 wt %, thermal conductivity of the composite increased up to 1.583 W m⁻¹ K⁻¹, and the temperature of final thermal decomposition was improved to 600°C. An increasing trend was found in the dielectric constant of the composites while the dielectric loss decreased with the increase in the fraction. An appropriate fraction of functionalized BN nanoplates in PI-based composites were necessary to meet the requirement of withstanding drilling forces for the interconnecting through holes of flexible circuits. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41889.

Particulate-filled polyarylene ether nitrile (PEN) composites were prepared using methyltriethoxy-silane-treated aluminium nitride (AlN) as the filler for thermal modification. The effects of AlN fraction, particle size and surface treatment on the thermal performance of PEN were investigated. The thermal conductivities of the composites increased when the AlN filler concentration was increased, as well as with decrement of the filler size. The thermal conductivity value of the composites increased up to 0.779 W m⁻¹ K⁻¹ when the AlN weight loading was 60 wt%. The trend of the thermal conductivities of the composites can be more efficiently predicted by theoretical models than empirical models. The composites exhibited stable performances of thermal decomposition and thermal expansion when AlN filler faction in the composites increased. © 2013 Society of Chemical Industry