INTERPENETRATING POLYMER NETWORKS AS HIGH-PERFORMANCE ELECTROELASTOMERS

摘要

Prestrain has generally been required for electroelastomers, also known as dielectric elastomers, such as the VHB 4910 acrylic elastomer, to attain high electromechanical strain and high elastic energy density. However, prestrain can cause several serious problems, including the use of a prestrain-supporting structure, a large performance gap between the active materials and packaged actuators, instability at interfaces between the elastomer and prestrain-supporting structure, and stress relaxation. We introduced difunctional acrylate monomers into highly prestrained acrylic films and subsequently cured the monomers to form a second elastomeric network. In the as-obtained Interpenetrating Polymer Networks (IPN), the additive network can effectively support the prestrain of the acrylic films and consequently eliminate the external prestrain-supporting structure. The IPN composite films without external prestrain exhibit electrically-induced strains up to 233% in area expansion. We have also introduced a trifunctional methacrylate monomer, trimethylolpropane trimethaacrylate (TMPTMA) in order to reduce the amount of the additive network in the composite films. The network formed from the trifunctional monomer is twice as effective as that formed from the difunctional monomer in supporting the high tension of the VHB network in the IPN composite films.