Effect of chemical components of emulsion polymerization in aqueous media on Na-MMT nanostructure by XRD analysis

The effects of chemical ingredients of emulsion polymerization reaction consisting deionized water as media of polymerization, styrene and methylmethacrylate (MMA) as nonpolar and polar monomers respectively, potassium persulfate (KPS) as initiator, Dodecylbenzenesulfonic acid sodium salt (DBS-Na) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) as conventional and reactive surfactants respectively, on nanostructural changes of pristine sodium Montmorillonite (Na-MMT) in aqueous media at ambient temperature and moderate stirring rate (150 rpm) was studied by X-ray diffraction (XRD) analysis. According to results, water can completely destroy the structural alignment of Na-MMT (in first stage with deflocculation and in second stage with defoliation), but it needs enough time (4 days). Addition of other chemical components in 48 h had different changes on water effect on nanostructure of Na-MMT. The interaction between AMPS and Na-MMT in aqueous media also was studied by thermal analysis (thermal gravimetery analysis and differential scanning calorimetery). It is illustrated that there are some strong interactions between AMPS and Na-MMT in water media which can lead to preparation of an end-tethered polymeric nanocomposite on Na-MMT layers through emulsion polymerization with this reactive surfactant.