The nanostructured thermosets containing poly(3-hexylthiophene) (P3HT) nanophases were prepared by incorporating poly(epsilon-caprolactone)-block-poly(3-hexylthiophene)-block-poly(epsilon-caprolactone) (PCL-b-P3HT-b-PCL) triblock copolymer into epoxy. The PCL-b-P3HT-b-PCL triblock copolymer was synthesized via the combination of the polycondensation of 2-bromo-3-hexyl-5-iodothiophene and the ring-opening polymerization of epsilon-caprolactone; it was characterized by means of H-1 nuclear magnetic resonance spectroscopy (H-1 NMR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The morphologies of the nanostructured thermosets were investigated by means of transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and dynamic mechanical thermal analysis (DMTA). The results of small angle X-ray scattering (SAXS) showed that the P3HT nanophases were formed via self-assembly mechanism of the triblock copolymer in epoxy thermosets. Compared to control epoxy, the nanostructured thermosets containing the conjugated nanophases significantly displayed the enhanced dielectric constants. In the meantime, the thermal conductivity of the nanostructured thermosets was also enhanced and increased with increasing the content of P3HT nanophases. (C) 2015 Elsevier Ltd. All rights reserved.