Keizo Akutagawa

Mesoscopic Mechanical Analysis of Filled Elastomer with 3D-Finite Element Analysis and Transmission Electron Microtomography

Abstract Analysis of deformation of the filled elastomer in mesoscopic scale was investigated with 3-D FEM (Finite Element Analysis). Combination of 3-D TEMT (Transmission Electron Micro Tomography...

Improved Tire Wet Traction through the Use of Mineral Fillers

Abstract Silica is widely used in passenger tire treads to improve the balance between wet traction and rolling resistance, compared to the balance achieved when the filler is strictly carbon black. Improvement in wet traction with silica is attributed to the difference in energy loss encountered at high frequencies. The energy loss difference is deduced from the difference in shift factors, determined by time temperature superposition in viscoelastic testing of silica compounds compared to carbon black compounds. Further investigation indicated that some mineral fillers other than silica showed similar behavior. Thus, some mineral fillers could improve tire wet traction without adverse effects on other tire performance traits.

Development of a three-dimensional tomography holder for in situ tensile deformation for soft materials

An in situ straining holder capable of tensile deformation and high-angle tilt for electron tomography was developed for polymeric materials. The holder has a dedicated sample cartridge, on which a variety of polymeric materials, such as microtomed thin sections of bulk specimens and solvent-cast thin films, can be mounted. Fine, stable control of the deformation process with nanoscale magnification was achieved. The holder allows large tensile deformation (≃800 μm) with a large field of view (800 × 200 μm before the deformation), and a high tilt angle (±75°) during in situ observations. With the large tensile deformation, the strain on the specimen can be as large as 26, at least one order of magnitude larger than the holders predecessor. We expect that meso- and microscopic insights into the dynamic mechanical deformation and fracture processes of polymeric materials can be obtained by combining the holder with a transmission electron microscope equipped with an energy filter. The filter allows zero-loss imaging to improve the resolution and image contrast for thick specimens. We used this technique to study the deformation process in a silica nanoparticle-filled isoprene rubber.