Thermal conductivity and dielectric properties of PEDOT:PSS-AlN filler reinforced water-soluble polymer composites

Poly(3,4-ethylenedioxythiophene):poly-(styrenesulfonic) (PEDOT:PSS) surface modification of aluminum nitride (AlN) fillers and the effects on thermal conductivity and dielectric properties of polyurethane (PU) based composites are investigated in this study. The compositions, microstructure, thermal stability, thermal conductivity, dielectric properties and volume resistivity of the PU based composites were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetry (TGA), optical thermal analyzer (OTA), impedance analyzer (IA), respectively. It was observed that the thermal conductivity and thermal stability of the PU composites increased with increasing AlN content. After proper processing, the AlN particles could form a continuous dispersion, which would form a thermally conductive pathway within the polymer matrix. By adding 0–50 wt% AlN particles, the PU composites thermal conductivity was increased from 0.209 to 0.476 W/m-K. Furthermore, the thermal conductivity can be promoted to 0.764 W/m-K using PEDOT:PSS surface modification. The dielectric properties of the composites can also be adjusted by PEDOT:PSS surface modification. The dielectric constant of the PU based composites was increased from 7.58 to 400 at 10 kHz by adding 0–3 wt% PEDOT:PSS, which can act as an attractive candidate material for packaging, dielectric and embedded capacitors.