Polystyrene Clay Nanocomposites Research Articles

Thermal and fire studies on polystyrene–clay nanocomposites

Thermal and fire studies on polystyrene–clay nanocomposites

Polymer–clay nanocomposites: exfoliation of organophilic montmorillonite nanolayers in polystyrene

A polymerizable cationic surfactant, vinylbenzyldimethyldodecylammonium chloride (VDAC) was synthesized for functionalization of montmorillonite (MMT) and preparation of exfoliated polystyrene–clay nanocomposites. Organophilic MMT was prepared by cationic exchange between inorganic ions of MMT and ammonium cations of VDAC in an aqueous medium. Dispersions of intercalated clay (VDAC–MMT) in styrene monomer formed gels. Shear thinning behavior of the gels was observed via rheological measurements. Polystyrene–clay nanocomposites were prepared by free radical polymerization of styrene containing dispersed organophilic MMT. Exfoliation of MMT in polystyrene matrix was achieved as revealed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The exfoliated nanocomposites have higher dynamic modulus and higher decomposition temperature than pure polystyrene.

Synthesis of polystyrene–clay nanocomposites

A reactive cationic surfactant vinylbenzyldimethyldodecylammonium chloride (VDAC) was synthesized for intercalation of montmorillonite (MMT), a smectic type of clay. Organophilic MMT was prepared by ion exchange between Na + ions in the clay and VDAC cations in aqueous medium. VDAC-intercalated MMT particles were easily dispersed and swollen in styrene monomer. Polystyrene–clay nanocomposites were prepared by free radical polymerization of styrene containing dispersed clay. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate that exfoliation of MMT was achieved. Polystyrene–clay nanocomposites have higher dynamic modulus than pure polystyrene (PS).

Thermal and fire studies on polystyrene-clay nanocomposites

Nanocomposites of polystyrene and several organophilic clays have been prepared by a bulk polymerization technique. The resulting polymers have an intercalated structure and show enhanced thermal stability, as measured by thermogravimetric analysis and cone calorimetry, relative to virgin polystyrene, even when as little as 0.1% of clay has been added.