Manipulating dielectric properties by modifying molecular structure of polymers

As one of the most important materials, polymeric dielectric is the key to tuning the dielectric performance of the resultant capacitors in a wide range for different applications. Depending onto the polarity of polymers and their dielectric performance under high electric field, polymeric dielectrics could be categorized into four classes, including linear dielectrics, normal ferroelectrics, relaxor ferroelectrics, and antiferroelectrics. By altering their molecular composition and controlling their aggregated structure chemically or physically, the dielectric performance of polymers could be facilely tuned from one to another. In this chapter, the dependence of dielectric properties of polymers on their chemical composition and condensed structures, including glass transition, crystalline and ferroelectric properties, and the polymer chain conformation, is carefully discussed. The synthesis and processing conditions of different polymer dielectrics are summarized and presented as well. The content and outline of this chapter are as follows.