Measuring Interfacial Strength in Clay, Sio2 and Carbon Black Filled SBR

MEASURING INTERFACIAL STRENGTH IN

CLAY, SiO₂ AND CARBON BLACK FILLED SBR

Emmanuel P. Giannelis

Materials Science and Engineering

Cornell University

Ithaca, NY 14853

The promise of unique performance, design flexibility, and lower cost has made nanocomposites the darling of the polymer community worldwide. The prospect of a new materials technology, which can function as low-cost alternative to high-performance composites has become irresistible to researchers around the world.  Persistent challenges with poor miscibility and control of interfacial strength, however, have prevented nanocomposites from realizing their full potential. In this study we use dielectric relaxation spectroscopy to evaluate the interfacial strength between SBR and various fillers and additives. In addition to the bulk polymer dynamics, there is also a second, much slower relaxation in SBR nanocomposites with clay. This slower relaxation is attributed to polymer motion at the SBR-clay interface and is a measure of interfacial strength. The interfacial glass transition temperature associated with this motion is 120 °C higher than the bulk glass transition temperature indicating strong interfacial interactions between SBR and clay that is absent from the corresponding carbon black filled SBR.