Biodegradable Bovine Gelatin/Na+-Montmorillonite Nanocomposite Films. Structure, Barrier and Dynamic Mechanical Properties

Biodegradable films based on gelatin and Na+-Montmorillonite were prepared by mixing of gelatin solutions with ultrasonically pre-treated clay suspensions under controlled conditions. The DRX patterns and AFM images suggested that ultrasonication process resulted in homogeneously distributed layered silicates inside the matrix but not fully exfoliated. Transparency was retained, suggesting that filler is mostly distributed at the nanoscale. The results of DMA showed an improvement in storage modulus and shifts in tan delta peaks toward higher temperatures. The reduction in polar groups due to hydrogen interactions between gelatin and clay particles was evidenced by the decrease in surface hydrophilicity and WVP.