Interpenetrating polymer networks based on acrylic elastomers and plasticizers with improved actuation temperature range

The VHB 4910 acrylic elastomer, already exhibiting great efficacy at room temperature, was modified to enhance its actuation performance via two approaches. To eliminate the requirement of high pre-strain, interpenetrating polymer networks (IPNs) based on poly(trimethylolpropane trimethacrylate) were formed in the original acrylic network. Furthermore, plasticizing additives were used to reduce the glass transition temperature, broaden the operating temperature range, lower the elastic modulus (hence the electric field required for actuation) and decrease the viscoelastic loss (to increase response speed). Dibutoxyethoxyethyl formal (DBEF) was found to be a highly effective plasticizing agent. For a relaxed IPN film containing 40 wt% DBEF actuated at -40 degrees C with an applied voltage of 6.5 kV, a large deformation (215% in areal expansion) is demonstrated. (C) 2010 Society of Chemical Industry