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Increasing the actuation characteristics of dielectric elastomer actuators (DEAs) under low electric field strength without compromising the elasticity and breakdown strength is still one of the great challenges in application field. Herein, we propose a simple, efficient, and controllable strategy to prepare dielectric elastomers with intrinsically good integrated properties by introducing styrene ethylene butylene styrene (SEBS) in thermoplastic polyurethane (TPU). Combined with experiments and molecular dynamics simulation, we find that the SEBS is uniformly dispersed in TPU matrix and a good interface structure is formed by pi–pi interaction and entanglement. The above characteristics lead to the destruction of the hydrogen bond network of TPU and the formation of single aggregation structure. Consequently, much decreased Young's modulus (Y) and enhanced breakdown field (Ebr) are achieved. Especially, when the content of SEBS is 4.76 wt%, the blend shows a desirable Y of 2.4 MPa and a much improved Ebr (118 kV mm−1), which is about 59% lower and 42% higher than those of TPU, respectively. As a result, the maximum electrical strain area of the dielectric blend elastomer reaches 4.7%, which is 250% higher than that of pure TPU under the same electric field strength. [ABSTRACT FROM AUTHOR]

The addition‐type liquid silicone rubber (ALSR) co‐filled with spheroidal Al2O3 and flaky BN was prepared by the mechanical blending and hot press methods to enhance the thermal, electrical, and mechanical properties for industrial applications. Morphologies of ALSR composites were observed by scanning electron microscopy (SEM). It was found that the interaction and dispersion state of fillers in the ALSR matrix were improved by the introduction of BN sheets. Thermal, electrical, and mechanical performances of the ALSR composites were also investigated in this work. The result indicated that the thermal conductivity of ALSR can reach 0.64 W m−1 K−1 at the loading of 20 wt% Al2O3/20 wt% BN, which is 3.76 times higher than that of pure ALSR. The addition of Al2O3 particles and BN sheets also improve the thermal stability of ALSR composites. Moreover, pure ALSR and ALSR composites showed relatively lower dielectric permittivity (1.9–3.1) and dielectric loss factor (<0.001) at the frequency of 103 Hz. The insulation properties including volume resistivity and breakdown strength were improved by the introduction of flaky BN in the ALSR matrix. The volume resistivity and characteristic breakdown strength E0 are 6.68 × 1015 Ω m and 93 kV/mm, respectively, at the loading of 20 wt% Al2O3/20 wt% BN. In addition, the mechanical characteristics including elongation at break and tensile strength of ALSR composites were also enhanced by co‐filled fillers. The combination of these improved performances makes the co‐filled ALSR composites attractive in the field of electrical and electronic applications. [ABSTRACT FROM AUTHOR]

ABSTRACT The properties of the polymer nanocomposites (PNCs), consisting low density polyethylene (LDPE) and magnesium oxide nanoparticles (MgO-NPs), were systematically discussed in this paper. The shear mixing time and MgO concentration were considered as the two factors affecting the dispersion state, which was found to be effective to change the crystallinity and the mechanical performance of MgO/LDPE PNCs. A reduction in the dynamic shear viscosity was observed when the concentration of MgO-NPs at a relative low level, which was also dominant by the dispersion states of MgO-NPs. Evident enhancement of the static yield stress was revealed only by introducing a minute amount of MgO-NPs (0.25 wt %). Meanwhile, the elastic and loss modulus were also found to be dependent on the dispersion state of MgO-NPs. A positive increase in dielectric permittivity was identified by uniaxial stretching the MgO/LDPE PNCs strips owing to the orientation enhancement of internal microstructure. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43038. [ABSTRACT FROM AUTHOR]

ABSTRACT Polymer composites with polystyrene (PS) as matrix and (Ba0.5Sr0.4Ca0.1)TiO3 (BSCT) as fillers are prepared by solution casting method. It is found that the dielectric constant of the prepared BSCT/PS composites increases with increasing filler content over the frequency range from 100 Hz to 500 MHz. And the dielectric properties of the composites show a good temperature independency over the range of −30°C to 80°C. For the composite with 50 vol % filler content, the dielectric constant and dielectric loss are comparable with the literature values reported for other PS composites used for microwave substrate. Several theoretical models are used to compare with the experimental data of the dielectric constant of the composites. The microstructure and thermal properties of the composites were also studied. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41398. [ABSTRACT FROM AUTHOR]

The dielectric properties, elastic modulus, and electromechanical responses of dielectric elastomers (DEs) consisting of silicone rubber and carbon black (CB) incorporated with BaTiO3 (BT) were studied. When compared with single filler/rubber composites, the resulting three-component nanocomposites yielded very abnormal phenomena. They might be attributed to the interactions between the two kinds of fillers. The increase in concentration of CB (BT) would play a destructive role to the network structure formed by BT (CB) particles. The maximum electromechanical strain of the nanocomposites achieved at mass fraction mCB = 0.03 and mBT = 0.06. The resultant electromechanical strain would be attributed to the large dielectric permittivity in the three-component nanocomposites, in which the BT particles themselves have a high dielectric permittivity and the electrical networks of CB particles have a contribution on the increase in dielectric permittivity of the three-component nanocomposites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]