Structure of polymer/clay nanocomposites, a molecular modelling perspective

Abstract

The search for renewable biodegradable materials to replace conventional oil-based plastics is a fast-growing research area as it provides an important factor for the sustainable growth of the packaging industry. In this regard, clay-containing composite materials have numerous current and potential commercial applications. However, the interaction between clay and polymer, i.e. Poly(ethylene glycol), is influenced by many factors, such as the nature of the clay, length and nature of the polymer chain, hence, in this work polymer/clay nanocomposite is studied both ex`perimentally and theoretically. Structural and thermodynamic properties of formulated nanocomposites are probed using XRD and TGA techniques and then compared with corresponding values derived from a series of Molecular Dynamics simulations of intercalated polymer/clay nanocomposites. For the first time, the developed potential models were able to predict realistic basal spacing of poly(ethylene glycol)/clay nanocomposite. The simulation also revealed the structure of the interlayer on a molecular level, which greatly benefited the understanding of the formation of polymer/clay coatings. The swelling dynamics, energetics and structure of the clay interlayers are examined. Particular attention is paid to the behaviour of polymer and water when they coexist in the clay interlayer.