Preparation of polystyrene/montmorillonite nanocomposites: optimization by response surface methodology (RSM)

摘要

Preparation of polystyrene (PS)-montmorillonitenanocomposites was carried out in 3 steps: purification anddetermination of the cation exchange capacity (CEC) of clay, synthesisof organoclay, and preparation of nanocomposites. In organoclaysynthesis, 3 types of surfactants, long-chained(cetyltrimethylammonium bromide (CTAB)), short-chained(tetraethylammonium bromide (TEAB)), and ringed(benzyltriethylammonium bromide (BTEAB)), were used. Gallerydistances of pure clay and organoclays (CTAB-O, TEAB-O, and BTEAB-O)were determined by X-ray diffraction (XRD) analysis as 1.25, 2.09,1.52, and 1.63 nm, respectively. Preparation of nanocomposites wascarried out by in situ polymerization. Composites, containing 2%,4%, and 6% organoclay by mass, were characterized by XRD, thermogravimetric analysis (TGA), gel permeation chromatography (GPC),and transmission electron microscope (TEM). The synthesizednanocomposites showed an exfoliated structure and a higherdecomposition temperature in comparison with pure PS. A new approachwas tried in nanocomposite preparation using response surfacemethodology (RSM).