A dipolar silicone dielectric elastomer and its composite with barium titanate nanoparticles

This paper offers a simple, low-cost, and effective method to prepare high-performance dielectric elastomer. 4-chorophenethyl alcohol as dipole functionalizes crosslinker and then the functional crosslinker is utilized to prepare a novel dipolar silicone elastomer (SRCl). The introduction of dipole reduces regular arrangements of molecular chains and the dispersive crosslinking is formed in SRCl. The dipolar crosslinkers are evenly distributed in the crosslinking network, so the mechanical, dielectric, and electromechanical properties are improved. The dielectric elastomer actuator made of the SRCl with 15% dipoles exhibits a maximum actuated strain of 9.97% and the SRCl with 12% dipoles shows the highest breakdown field strength of 73.33 V/μm, which is increased by 156% and 52%, respectively, compared with pure silicone elastomer (SR, 3.89% at 48.23 V/μm). In addition, barium titanate (BT) nanoparticles as filler is mixed with SRCl to prepare the SRCl/BT composites. It is found that the dielectric property of composites is dominated by the matrix polarity. The electrostatic interaction between hydroxyl groups on BT nanoparticles and chlorine groups on the SRCl matrix improves the dispersion of BT nanoparticles in SRCl matrix. The maximum actuated strain of SRCl/20% BT (11.97%) is 3 times as high as SR (3.89%).