227a Exfoliated Nanocomposite Powders- a Route to Lower-Cost Fillers

Sudhakar Balijepalli, Daniel Simmons, Irina Graf, and Nickless Brian. The Dow Chemical Company, 1702 Bldg., Midland, MI 48674

The ideal filler for an elastomer, particularly for the tire industry, would improve mechanical properties while providing other benefits such as low rolling resistance, lower abrasion, and higher weather resistance. Although the state-of -the-art carbon blacks offer a low cost means of providing these property enhancements, they require non-renewable raw materials. Accordingly, it would be desirable to find a property enhancing filler material that is advantageously derivable from renewable resources, that is inexpensive to make, and is easy to use.

A unique approach is to exfoliate clay in carbonaceous precursor like starch, and to convert the starch to carbon soot. Exfoliated clays in soot are low-cost dual composites that exploit the high modulus plates of clay in soot as the reinforcing agent while the surrounding amorphous soot acts as the dispersant into a polymer matrix.

The paper wil describe the creation of these composites with regards to the clay types and their loading on creating well-exfoliated composites. Clays such as Laponite, Montmorillonite are shown to be well exfoliated within the starch matrix and subsequent to the carbonization process, in the soot. Some aspects of dispersion into polymers and their attendant properties will also be described.