Advanced dielectric elastomer based on optimized thermoplastic polyurethane–styrene ethylene butylene styrene blend: Experiment and simulation

摘要

Abstract 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.