Expandable Polystyrene-Clay Nanocomposites: Exploiting Water as Blowing Agent

Expandable polystyrene (EPS) is an important industrial product. A standard procedure for the production of EPS is based on the suspension polymerization of styrene and pentane mixture, producing beads with high volatile organic hydrocarbons content and high flammability. To reduce or obviate these disadvantages two mechanisms have been proposed; replacement of pentane isomers with water as a harmless blowing agent [1], and insertion of layered silicated additives which are self a fire retarder [2]. In this work, the role of loading level and surface characteristics of layered silicates (the type, packing density and the size of grafted organic modifier) on expandability, morphology and flammability of water expandable polystyrene-clay nanocomposite (WEPSCN) are investigated