Nanoclay Nucleation Effect in the Thermal Stabilization of a Polymer Nanocomposite: A Kinetic Mechanism Change

The enhanced thermal stability of polymer-clay nanocomposites over the original polymers is one of their most interesting features, and it has been profusely studied within the last decades. Here, a thorough kinetic analysis of polystyrene and a montmorillonite-polystyrene nanocomposite has been performed making use of state-of-the-art kinetic procedures. It has been found that the degradation mechanism changes from a chain scission process for the polymer to a complex two-step nucleation-driven reaction for the nanocomposite. This mechanism change can explain the delayed onset of degradation found in the nanocomposite. Moreover, observation by transmission electron microscopy (TEM) has shown that the clay platelets within the composite could act as nucleation centers for the decomposition.