Preparation of polymer-clay nanocomposites with improved flame retardancy

Nanotechnology and nanoscience are multidisciplinary fields that combines chemistry and physics. Nowadays, most of the studies conducted in this area, are about materials containing nano- sized particles. Nanocomposites that have widespread utilization are defined as multiphase materials where at least one of the phases has a dimension in the nano-scale. They have variety of commercial application fields such as medical, electronic, textile, catalysis, informatics and space sectors. Due to the fact that matter at the nano-scale has different properties as compared with macro-scale, these application fields are increasing. The main aim of this study is to preparation of polymer/clay nanocomposites with improved flame retardancy. Montmorillonite clay (MMT) was pre-modified using quaternized derivative of Bis(3-aminophenyl) phenyl phosphine oxide (BAPPO) via ion exchange between Na+ ions in the clay and BAPPO cations in aqueous medium. Polystyrene–clay nanocomposites were prepared by free radical polymerization of styrene containing dispersed clay. The resultant nanocomposites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of increased nanofiller loading in thermal properties of the nanocomposites was investigated by thermogravimetric analysis (TGA) and differantial scanning calorimetry (DSC). Flame retardancy properties were investigated by Limiting Oxygen Index and UL 94 flamability test.