▎ 摘　　要

Poly(methyl methacrylate)-functionalized graphene/polyurethane (MG-PU) dielectric elastomer composites were synthesized. MG was prepared by atom transfer radical polymerization (ATRP) and used as conducting filler. The microstructure of MG and MG-PU was characterized by SEM, TEM and XRD. The thermal degradation, mechanical, dielectric and electromechanical properties were investigated. The three-dimensional (3D) electric field induced displacement and strain of dielectric elastomer surface was observed and measured for the first time. Comparing with pure PU elastomer, the dielectric properties and electric field induced strain performance of MG-PU dielectric elastomer composites were significantly improved. The 1.50 wt% MG-PU film had high relative permittivity and electric field induced strain of 28.21 and 32.8%, respectively. (C) 2014 Elsevier B.V. All rights reserved.