STRUCTURE AND PROPERTIES OF GELATINE/MONTMORILLONITE NANOCOMPOSITE FILMS

J. F. MARTUCCI; R.A. RUSECKAITE

Recent Advances in Research on Biodegradable Polymers and Sustainable Composites

Nova Science Pub

Lugar: New York; Año: 2008; p. 27 - 36

Homogenous and transparent gelatine/montmorillonite films intended to be applied as packaging materials were obtained via simple mixing of gelatine solutions with ultrasonically pre-treated clay suspensions under controlled conditions. For clay loadings between 1 to 10wt.%, X ray diffraction patterns and atomic force microscopy images indicate that full exfoliation has not occurred and the structure can be described as intercalated and partially exfoliated. Water resistance, water vapour permeability and transparency were analyzed in order to evaluate the some properties of the nanocomposite films as packaging materials. It was found that the surface hydrophobicity of the films increased with increasing clay content. In association with this, the water vapour permeability and moisture absorption were seen to decrease in the nanocomposites. The decrease in permeability was mostly related with a decrease in diffusivity. Transparency was retained, at least for 15wt.% clay, suggesting that filler is mostly distributed at the nano-scale. The results of dynamic mechanical analysis showed an improvement in storage modulus over the temperature range analyzed together with shifts in tan d peaks toward higher temperatures. Therefore nanocomposites may extend the temperature application range of gelatine films. The main conclusion from this work is that montmorillonite can be used to enhance mechanical properties, water resistance and barrier properties of gelatine films of interest in, for instance, packaging applications.