Effect of fluorine hybridization on dielectric response of epoxy polymer

Dielectric response of polymer dielectrics determines their applications in electronic devices. Although fluoropolymers were widely accepted in communication technology, electronic packing and electrical insulating for their extraordinary dielectric properties, the underlying effect of fluorine hybridization on the dielectric response of polymers is still unclear. Here, surface fluorination was conducted to construct fluorine hybrid epoxy resin (EP), and the dielectric response of EP before and after fluorination was studied. It was found that at low temperature, the electronic polarization was dominated on the dielectric response. The fluorine hybridization reduced the electronic polarization, which led to a lower permittivity of the fluorinated EP. However, at a higher temperature, the fluorine hybridization increased the thermal expansion coefficient and enlarged the free volume fraction, which allowed flexible reorientations of dipoles and led to an enhanced dipolar polarization, and thus, it proved an enhanced permittivity for fluorinated EP. Therefore, the effect of fluorine hybridization on dielectric response of EP polymers was temperature-dependent, with the low-temperature-dominated electronic polarization and high-temperature-dominated dipolar polarization, respectively. This work revealed the influence of fluorine hybridization on dielectric response of epoxy polymers and could promote the application of organic dielectrics in communication and electronic devices.