Ultrasonic studies of polymer composites with inorganic nanotubes

The temperature dependencies of longitudinal ultrasonic attenuation and velocity in several groups of new polyurea elastomers and poly(ε-caprolactone) composites were measured. In region of the glass transition the large ultrasonic attenuation maxima were observed. These peaks have relaxation behavior and can be approximated by temperature dependant relaxation time described by Arrhenius equation. The position of ultrasonic attenuation maxima and activation energy of relaxation process depends on the structure of the polyurea network. The ultrasonic relaxation peak in poly(ε-caprolactone) is also related to glass transition. The influence of inorganic nanotubes and nanowires in polyurea elastomers and poly(ε-caprolactone) is also discussed.