Dielectric and thermal properties of nanostructured epoxy composites involving reactive POSS and c-BN

Epoxy composites containing either Polyhedral Oligomeric Silsesquioxanes (POSS) or cubic boron nitride (c-BN), in addition to a multiphase composite with both, POSS and c-BN, were fabricated and studied. A reactive liquid POSS, namely a Triglycidylisobutyl-POSS (TGIB-POSS) was used in a content of 1 wt% for the single phase and the multiphase composite. Submicrometric c-BN was used in a content of 5 wt% for the respective single phase composite as well as in the multiphase sample to create multifunctional nanostructured composites. The test specimens were characterized by Broadband Dielectric Spectroscopy (BDS) and thermal conductivity measurements. While the single phase POSS composite revealed a slightly enhanced thermal conductivity, the single phase c-BN composite showed an improvement by 26 % in thermal conductivity compared to neat epoxy. Additionally, the dielectric and thermal properties of the multiphase composite containing 1 wt% POSS and 5 wt% c-BN, were found to be dictated by the submicrometric c-BN particles.