Polystyrene nanocomposite materials by in situ polymerization into montmorillonite–vinyl monomer interlayers

Abstract

A different series of new polystyrene-clay nanocomposites have been prepared by grafting polymerization of styrene with vinyl-montmorillonite (MMT) clay. The synthesis was achieved through two steps. The first step is the modification of clay with the vinyl monomers, such as N,N-dimethyl-n-octadecyl-4-vinylbenzyl-ammonium chloride, n-octadecyl-4-vinylbenzyl-ammonium chloride, triphenyl-4-vinylbenzyl-phosphonium chloride, and tri-n-butyl-4-vinylbenzyl-phosphonium chloride. The second step is the polymerization of styrene with different ratios of vinyl-MMT clay. The materials produced were characterized by different physical and chemical methods:(1) IR spectra, confirming the intercalation of the vinyl-cation within the clay interlayers; (2) thermogravimetric analysis (TGA), showing higher thermal stability for PS-nanocomposites than polystyrene (PS) and higher thermal stability of nanocomposites with of phosphonium moieties than nanocomposites with ammonium moieties; (3) swelling measurements in different organic solvents, showing that the swelling degree in hydrophobic solvents increases as the clay ratio decreases; (4) X-ray diffraction (XRD), illustrating that the nanocomposites were exfoliated at up to a 25 wt % of organoclay content; and (5) scanning electron microscopy (SEM), showing a complete dispersion of PS into clay galleries. Also, transmission electron microscopy (TEM) showed nanosize spherical particles of $ 150-400 nm appearing in the images.

New protein-resistant coatings for water filtration membranes based on quaternary ammonium and phosphonium polymers

“…The flask was cooled to room temperature, and the solids were filtered off and washed with hexanes to afford the product 5d as a white solid (7.40 g, 98% yield). The characterization data for this compound matched literature values [48].…”

Evaluation of the confinement effect of nanoclay on the kinetics of styrene atom transfer radical polymerization

“…By high-speed ultracentrifugation and then passing the solution through a 0.2 lm filter, the unattached polymer chains were separated from the anchored ones after passing through the filter pores. 25 The tethered chains were cleaved from the layers by a reverse cation exchange procedure: Nanocomposite (2 g), 125 mL of THF/Methanol (4/1, v/v) solution, and LiBr (0.1 g) were refluxed in a 150 mL round-bottom flask equipped with a condenser and stirring bar for 6 h. The cleaved polystyrene samples were obtained after centrifugation. The solution was poured into methanol (500 mL) to precipitate the polymer chains.…”

Investigation and Preparation of High Impact Polystyrene Nanocomposites

“…These materials have been widely used in areas of electronics, transportation and construction products. They offer attractive combination of stiffness and toughness, which are difficult to attain from the individual component alone [1]. The PCNs posess many desirable properties, such as enhanced gas barrier, fire retardant, corrosion resistance, and ionic conductivity; increased thermal stability and mechanical strength; and decreased absorption in organic liquids [2].…”