Abstract
Lignin–montmorillonite nanocomposite films have been prepared in order to elucidate the possibility for flexible substrate film of electronic devices. The prepared films possessed multi-layer stacking structure having intercalated lignin between nanosheets of silicate. They showed 18–57 g m−2 day−1 of water vapor transmission rate and 6–7 ppm K−1 of linear coefficient of thermal expansion after annealing up to 503 K, superior to the characters of the industrial polyimide film. The characteristics are originated from the clay mineral that has high aspect ratio silicate structure and the difference in water vapor penetration was derived from hydrophilicity of polymers. Although arithmetical mean roughness, Ra, was under 0.3 µm by AFM, the films were followed by drawing electronic wiring using Ag ink, resulting in the good formation of printed circuit due to the compatibility of the ink to the substrate material. Consequently, we found that lignin–montmorillonite nanocomposite films are applicable for the substrates of electronic devices.
