Impact of Clay Nanoparticles on Structure and Relaxation of a Polar Polymer Peggy Cebe, Department of Physics and Astronomy Tufts University, Medford, MA 02155 Background: When polymers are mixed with clay, the clay nanoparticles often enhance the properties of the host polymer. Clay acts as a two-dimensional reinforcement, improving the mechanical, thermal, and electrical behavior of polymers. We are studying the effects of the addition of clay on polar polymers with applications as electrical transducers and sensors. Objective: To measure the dynamic electrical and mechanical response of polymer-clay nanocomposites as a function of temperature and amount of clay. The selected polymer is a polar polymer, poly(vinylidene fluoride), PVDF. The clay is LucentiteTM, a synthetic silicate, organically modified to enhance its interaction with the polymer host. Figure – As clay content increases from 0% (pure PVDF, red curves) to 0.1% (green) to 4% (blue) OMS: a.) X-ray diffraction shows a change from alpha to polar beta crystallographic phase; b.) Dielectric loss increases in magnitude at Tg, the glass transition of PVDF, and Tg shifts slightly to high temperature indicating improvement in thermal transition temperature. a b Data from: Lei Yu, B. Seyhan Ince-Gunduz, and Peggy Cebe. Preprints of the American Chemical Society, Division of Polymeric Materials: Science and Engineering, Vol. 97, Fall (2007), p. 446.