High-κ Polyimide-Based Dielectrics by Introducing a Functionalized Metal-Organic Framework

In this work, novel metal-organic framework/polyimide (MOF/PI) composite films possessing dielectric properties were synthesized via a solution blending method. UiO-66 and UiO-66-NH₂ nanoparticles were first prepared by a hydrothermal method and added into PI to obtain the composite films. Compared with pure PI, the dielectric properties of the MOF/PI composites were substantially enhanced. The amine functionalization gave UiO-66-NH₂/PI composite films better dielectric properties in comparison with UiO-66/PI composite films because of improved interaction between PI and UiO-66-NH₂. It showed that the dielectric constant of the PI composite film containing 20 wt% UiO-66-NH₂ is 8.8 at 10² Hz, which was approximately 2.5 times that of the pure PI (3.5 at 10² Hz). The dielectric loss of the composite film was less than 0.034. Moreover, the breakdown strength of 20 wt% UiO-66-NH₂/PI composite films was found to be 208 kV/mm. We describe this new perspective for the preparation of high-performance polymer-based dielectric materials and their application as electrical materials.