Improved Electromechanical Performance of Dielectric Elastomers via Constructing an All-Organic Composite Structure

Dielectric elastomers (DEs) can be deformed in response to an electric field. However, an excellent electro-actuated strain of DEs is usually achieved at high applied voltages, which severely limits their application range. Moreover, flexible DEs are susceptible to electromechanical breakdown, which directly affects their operational life. Herein, a novel all-organic DE composite was designed. First, isooctyl 3-mercaptopropionate (IOMP)-grafted methyl vinyl silicone (MVQ) was prepared to enhance the polarization and reduce cross-link density of macromolecular chains. Furthermore, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) was incorporated into the MVQ–IOMP matrix. The positively charged NTCDA can capture free charges through strong electrostatic interaction, thus enhancing the breakdown strength of DEs. Ultimately, a 1 wt % NTCDA/MVQ–IOMP0.75 DE composite obtains an extremal actuated strain of 52.9% under 45.2 V/μm and a maximum actuated strain of 37.3% under its safe electric field (36.1 V/μm). Consequently, this work provides a feasible way for preparing advanced DE composites.