Physical and Mechanical Properties of Nanocomposite Barrier Film Containing Encapsulated Nanoclay

Waterborne poly(styrene-co-butyl acrylate) was prepared via miniemulsion polymerization in which nanoclay (Cloisite (R) 30B, modified natural MMT) in different concentrations was encapsulated. Scanning electron microscopy, X-ray diffraction, and transmission electron microscopy confirmed the encapsulation and intercalated-exfoliated structure of Cloisite (R) 30B within poly(styrene-co-butyl acrylate). The effect of nanoclay content on water vapor permeability, water uptake, oxygen permeability, thermal, and mechanical properties of thin films containing 1.5, 2.56, 3.5, and 5.3 wt % encapsulated Cloisite (R) 30B in poly(styrene-co-butyl acrylate) was investigated. The presence of encapsulated Cloisite (R) 30B within the polymer matrix improved tensile strength, Young's modulus, and toughness of the nanocomposites depending on the nanoclay content. Water vapor transmission rate, oxygen barrier properties, and thermal stability were also improved. The results indicated that the incorporation of Cloisite (R) 30B in the form of encapsulated platelets improved physicomechanical properties of the nanoclay-polymer composite barrier films. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3284-3291, 2010