Influence of Residual Solvent on the Dielectric Performances of Polymer Dielectrics

Organic solvents are usually essential in the preparation of polymers with excellent insulating performances. However, the solvents, especially with a high boiling point, are difficult to be removed completely during composite fabrication and solution casting. This research clarifies the effect of solvent based on epoxy resin (EP). The quality of the epoxy containing solvents shows an acceptable change before and after curing, which indicates the target quantitative solvent has been successfully sealed. The dielectric constant of the material increases with the increase of solvent polarity. Additionally, the dielectric loss value of containing polar solvents is higher than that of pure EP, which may be assigned to the synergism of “extra electric dipole” orientation polarization and available segment motion. This work revealed that the type of solvent has a significant influence on the dielectric performance of epoxy resin. The reasonable choice of solvent can extremely reduce the influence on the final performance of polymer dielectrics.