A Simple Method To Improve the Clarity and Rheological Properties of Polymer/Clay Nanocomposites by Using Fractionated Clay Particles

作者：Cipriano Bani H; Kashiwagi Takashi; Zhang Xin; Raghavan Srinivasa R^*

来源：ACS Applied Materials & Interfaces, 2009, 1(1): 130-135.

DOI：10.1021/am8000693

• polymer nanocomposites
• organoclay
• rheology
• transparency

We present a simple method to improve the transparency and rheological properties of polystyrene/organoclay nanocomposites. Such composites are typically prepared using organophilic derivatives of commercial montmorillonite (MMT) clays that contain a wide range of particle sizes. Our approach is to fractionate the native MMT clay to exclude large aggregates and then modify the fractionated clay (FMT) by a surfactant treatment (the resulting organoclay is termed o-FMT). Polystyrene nanocomposites made From the o-FMT are then compared with those made from a commercial organoclay having the same surfactant treatment. The o-FMT-based composites exhibit much better rheological properties (e.g., their elastic moduli at low frequencies are similar to 10 times higher) at equivalent mass loadings. Moreover, the o-FMT-based materials also have better transparency: e.g., a 10% o-FMT sample transmits as much light as a sample with 5% commercial clay. Transmission electron microscopy confirms that these differences in properties are related to microscructural differences; i.e., large aggregates are generally absent in the o-FMT samples. Clay fractionation may thus be a general strategy to enhance the properties of polymer/clay nanocomposites.

• 出版日期2009-1