Enhanced dielectric properties of high glass transition temperature PDCPD/CNT composites by frontal ring-opening metathesis polymerization

Frontal ring-opening metathesis polymerization was used to in situ prepare polydicyclopentadiene (PDCPD)/carbon nanotubes (CNTs) and PDCPD/CNT-NH2 composites with high glass transition temperature. Compared with PDCPD/CNT composites, PDCPD/CNT-NH2 composites have similar dielectric constants, but their loss tangent significantly reduces. The uniform dispersion of CNT-NH2 leads to the formation of dielectric interfacial polarization. The results of dynamic mechanical analysis (DMA) showed that the glass transition temperature (Tg) of the composites increased with the increase of filler. With the increase of the filler, the elongation at break of the PDCPD/CNT composites decreased, while the elongation at break of PDCPD/CNT-NH2 composites increased, reaching up to 17% because of the stronger interfacial affinity. The PDCPD/CNT-NH2 composites exhibited high dielectric permittivity (47.5 at a frequency of 100 Hz) that originates from the interfacial polarization between PDCPD and CNT-NH2, and the nonconducting –NH2 groups can prevent the conductive path of CNTs and support a low loss tangent (0.096). High Tg PDCPD/CNT-NH2 composite with enhanced dielectric properties was prepared by a simple and quick one-step reaction method of FROMP. Keywords: Polydicyclopentadiene; Composites; Carbon nanotubes; Dielectric properties, Interfacial polarization