Carbon nanotubes/cyanate ester composites with low percolation threshold, high dielectric constant and outstanding thermal property

A novel kind of multi-walled carbon nanotubes (MWCNTs)/cyanate ester (CE) composites with low percolation threshold, high dielectric constant and excellent thermal property was developed. In order to investigate the effect of the surface nature of MWCNTs on the morphology and properties of the composites, MWCNTs and surface treated carbon nanotubes (MWCNTs–OH) were used to prepare two sorts of composites, coded as M/CE and M–OH/CE, respectively. Results show that increasing the content of MWCNTs or MWCNTs–OH, the dielectric constant of both kinds of composites initially increases until reaches the maximum value, and then decreases. In addition, when the percolation occurs, dielectric constant and loss of both kinds of composites decrease quickly with the increase of the tested frequency. The addition of MWCNTs into CE decreases the glass transition temperature and thermal stability, while the incorporation of MWCNTs–OH significantly improves the thermal stability of CE resin.