Barrier properties of poly(benzimidazole)-layered silicates nanocomposite materials

The preparation of the composite materials based on poly(benziimidazole) and layered silicates was investigated. The prepared composite materials are characterized for their barrier properties using a mixture of liquids such as methanol and water. Poly(benziimidazole) was supplied as a 10 % solution in dimethylacetamide and both natural and synthetic silicates were used. Montmorillonite (MM804), a natural layered silicate was utilized to prepare the nanocomposite. In the first stage, a dispersion of the silicates in dimethylacetamide solvent was obtained and the dispersion was added to 5 % polymer solution. The solution was stirred until a homogeneous system was obtained. The polymer containing silicate dispersion was cast on a silylated glass plate. Methanol and water barrier studies were measured across plain poly( benzimidazole) and nanocomposites by pervaporation. It was found that the addition of functionalized laponite into poly( benzimidazale) matrix decreased methanol/ water permeability.