Preparation of the Polymer-Clay Nanocomposites in Exfoliated State by Interface Stabilization

To suppress the repulsive interfacial energy between hydrophilic clay and a hydrophobic polymer matrix for polymer-clay nanocomposites, a third component of amphiphilic nature such as poly(e-caprolactone) (PCL) was introduced into the styreneacrylonitrile copolymers (SAN)/Na-montmorillonite system. Once e-caprolactone was polymerized in the presence of Na-montmorillonite, the successful ring-opening polymerization of e-caprolactone and the well-developed exfoliated structure of PCL/Namontmorillonite mixture were confirmed. Thereafter, SAN was melt-mixed with PCL/Na-montmorillonite nanocomposite, and the SAN matrix and PCL fraction were completely miscible to form a homogeneous mixture with retention of the exfoliated state of Na-montmorillonite, exhibiting that PCL effectively stabilizes the repulsive polymerclay interface and contributes to the improvement of the mechanical properties of nanocomposites.