Flexible high dielectric polystyrene/ethylene‐α‐octene copolymer/graphene nanocomposites: Tuning the morphology and dielectric properties by graphene's surface polarity
Milad Goodarzi, Gholamreza Pircheraghi, Hossein Ali Khonakdar, Volker Altstädt
Abstract
Abstract The current research focuses on suggesting a new potential application of polymeric materials for capacitor applications by focusing on polystyrene (PS)/ethylene‐α‐octene copolymer (EOC) blends. Polymeric materials have high dielectric strength (≈ 200 for PS), good processability, and flexibility. However, their low dielectric constants make them not suitable for capacitor applications. Therefore, suggesting a method for enhancing their dielectric constant accompanied by low tan δ proposes an excellent substitute for commonly used ceramic dielectrics. The current article investigates the control of the dielectric properties of PS/EOC blends by manipulating the graphene nanoplatelets (GNPs) surface polarity. Results confirm that the localization site of the GNPs is mainly controlled by their surface polarities; this matter leads to the change of the morphology from sea/island for the pure blend to co‐continuous for the blend containing the most polar GNPs resulting in the best dielectric properties. This manipulation of the morphology by low concentration of GNPs (1.5 wt%) and therefore, dielectric properties result in high dielectric constant ≈ 55.8 at 10 MHz and low tan δ = 0.007, accompanied by high flexibility, which is the main drawback of ceramic capacitors, makes it a fantastic option for capacitor applications.