Actuator Performance of Dielectric Elastomers Comprising Hydrogenated Carboxylated Acrylonitrile-Butadiene Rubber/Nitrile Group-Modified Titanium Oxide Particles

Ryosuke Matsuno; Yota Kokubo; Shigeaki Takamatsu; Atsushi Takahara

doi:10.1021/acsomega.0c06219

Actuator Performance of Dielectric Elastomers Comprising Hydrogenated Carboxylated Acrylonitrile-Butadiene Rubber/Nitrile Group-Modified Titanium Oxide Particles

ACS Omega. 2021 Mar 4;6(10):6965-6972. doi: 10.1021/acsomega.0c06219. eCollection 2021 Mar 16.

Authors

Ryosuke Matsuno^{1

2}, Yota Kokubo³, Shigeaki Takamatsu³, Atsushi Takahara²

Affiliations

¹ KOINE Project Division, Global Innovation Center (GIC), Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan.
² Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
³ Sumitomo Riko Company Limited, 1, Higashi 3-chome, Komaki-shi, Aichi 485-8550, Japan.

Abstract

We prepared a dielectric elastomer actuator composed of hydrogenated carboxylated acrylonitrile-butadiene rubber (HXNBR)/nitrile group (CN)-modified and non-modified titanium oxide (TiO₂) particles with insulation properties. The CN group-containing silane coupling agent was synthesized via a thiol-ene reaction between acrylonitrile and 3-mercaptpropyltrimethoxysilane and immobilized onto the TiO₂ particle surface. The HXNBR/CN-modified and non-modified TiO₂ particle composite elastomer showed a high relative dielectric constant and generated stress in a low electric field. The relative dielectric constant increased proportionally with the amount of CN-modified TiO₂ particles, showing a value of 22 at 100 Hz. As the dielectric constant increased, the volumetric resistivity decreased; however, the dielectric breakdown strength was maintained at 95 V/mm. The generated stress of the composite elastomer increased in proportion to the relative dielectric constant, showing a maximum of 1.9 MPa. The card-house structure of TiO₂ particles in the composite elastomer is assumed to suppress the dielectric breakdown in a low electric field. Thus, we demonstrated that an elastomer containing a high dipole group on an insulating particle surface is capable of improving the power performance of soft actuators.