Preparation And Study Of High Dielectric Proformance Dielectric Elastomer Material

Dielectric elastomer (DE) as a new type of electroactive polymer(EAP), DE can induce surprisingly large actuation strain under electric field. DE has a widely application prospect. But in recent reported about DE, the dielectric constant of matrix are not ideal, in order to obtain the high actuation strain, but the high voltage restricted practical use. So, how to obtained high actuation strain under low electric field as a key.According to the theory of dielectric actuation strain, the key is to maintain the high dielectric constant and keeping the elastic modulus at low level.Due to the graphene oxide (GO) and carbon nanosphere (CNS)contain oxygen containing groups.The GO coated CNS (GO@CNS)fillers were preparation for the π-π conjugate and hydrogen chemical bonds between oxygen containing functional groups exist in GO and CNS.Acrylic rubber (AR) as dielectric elastomer matrix blends with GO@CNS fillers. Thermally reduced can repair part of GO structure, and get rid of the part of oxygen containing functional groups. Thus the dielectric performance of the AR composites has been enhanced. According to the results the dielectric constant of AR composites at 103 Hz enhanced to 783 for the AR filled with 1.5 vol. % fillers. At same time, the dielectric loss of AR filled with 1.5 vol. % fillers maintain at low level (<1.04 at 103 Hz). In addition, the elastic modulus keeping at low level at same time.And at 6 kV/mm of pure AR obviously increased from 0.6% to 4.1% for the AR filled with 1.5 vol. % filler; the AR filled with 1.25 vol.%RGO@CNS actuated strain at 12 kV/mm is 6.1% hexaploid for the pure AR.Herein, we used a simple and effective approach to increase the actuated at low electric filed of thermoplastic polyurethane (TPU)through the disruption of the hydrogen bonds of TPU by blending with carboxylated nitrile rubber (XNBR). XNBR as proton donors disrupted the original N-H/C=0 hydrogen bonds between the TPU chains,improving the polarization ability of the chains, thus the TPU dielectric property of has been enhanced. At same time, the elastic modulus of TPU was obviously decreased due to the hydrogen bonds of TPU were disrupted by XNBR, and because XNBR with low elastic modulus, the XNBR/TPU blends elastic modulus decrease with the increasing of XNBR content. The dielectric constant increased and elastic modulus decreased of AR composites lead to a 820% increase in electromechanical sensitivity at 103 Hz and 210% increase in actuated strain at the low electric field of 18 kV mm-1.Our work provides a simple and effective method to produce a macroscopic and stable dielectric elastomer by polymer solution blending,moreover, largely enhanced the dielectric property at a low electric field of a dielectric elastomer composites, facilitating the application of DE in biological and medical fields.