Polybutadiene Dielectric Elastomers with high Dielectric Constant and Ultralow Dielectric loss via Tuning Grafted Polar Groups.

This study describes an easy and effective process for preparing a homogeneous polybutadiene (PB) dielectric elastomer with improved actuated strain by utilizing a photochemical thiol-ene click reaction. The carboxyl groups and various ester groups are used to grafting on the PB. Since the length of the alkyl chains of the ester groups would significantly influence the polarities of the carbonyl groups and hydrogen bonding effect, we carefully discuss the influence of polarity and hydrogen bonding effect on the dielectric properties and mechanical properties of the modified polybutadienes. Very interestingly, we find that the increment of dielectric constant of PB modified by carboxyl groups is the lowest one compared to other modified PBs with the ester groups. Meanwhile, the modified PBs with the ester groups could achieve pretty low dielectric loss factor. And finally, a high dielectric constant (3.6), low dielectric loss factor (0.0005) and large actuated strain (∼25%) of the modified polybutadienes could be achieved by the modified PBs with butyl acrylate groups. This study provides a simple and effective method for the designing and synthesizing a homogeneous high electromechanical performance dielectric elastomer with high dielectric constant and low dielectric loss. This article is protected by copyright. All rights reserved.