Comparison of poly(ethylene-co-acrylic acid) loaded Zn~(2+)-montmorillonite nanocomposites and poly(ethylene-co-acrylic acid) zinc salt

摘要

Novel nanocomposite films based on poly(ethyIene-co-acrylic acid) (PEAA) and zinc montmorillonite (Zn~(2+)-MMT) were fabricated using a solution casting method with water as the solvent. Transmission electron microscopy indicated that Zn~(2+)-MMT was distributed finely in the PEAA matrix. X-ray diffraction indicated that an ion exchange process occurs between Zn~(2+)-MMT and PEAA. The nanocomposites filled with a low Zn~(2+)-MMT loading increased the tensile strength and elongation at break. The significant improvements in these mechanical properties were attributed to the fine dispersion of Zn~(2+)-MMT in the polymer and the covalent interaction between the polymer chains and Zn~(2+) cations. Thermogravimetric analysis and differential thermal calorimetry confirmed that PEAA formed a network through the presence of Zn~(2+) cations. A poly(ethylene-co-acrylic acid) zinc salt (PEAAZn) film by hot pressing was introduced for comparison. Zn~(2+)-MMT improved the mechanical properties of the PEAA significantly compared to that of PEAAZn.