Gelatin-based blends and composites. Morphological and thermal mechanical characterization

Gelatin, a natural macromolecular proteic material from renewable resources, is widely used in many industrial applications. In this study gelatin scraps, deriving from pharmaceutical capsule productions, were turned into films by casting water solutions or suspensions producing flexible and consistent films. Gelatin was blended with poly(vinyl alcohol), a biodegradable synthetic polymer, in order to improve mechanical properties in the films. Gelatin was blended also with sugar cane bagasse, a lignin cellulosic waste from sugar cane processing. These blends showed good interface adhesion between gelatin and sugar cane fibers and mechanical properties of practical interest for up to 20% of sugar cane content by weight. Glutaraldehyde was used in different amounts as a cross-linking agent increasing elongation at break especially for amount above 1%. Morphology, thermal, thermomechanical, and mechanical properties of the samples were investigated by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and tensile tests, respectively. Cast films presented thermal and mechanical properties, which make them good candidates as biodegradable self-fertilizing mulching films.