Bio-nanocomposites films based on unmodified and modified thermoplastic starch reinforced with chemically modified nanoclays

Abstract

The use of polymers capable of being degraded by the action of microorganisms and/or enzymes without causing harmful effects is a strategy in waste management and environmental care. In this work, bio-nanocomposites based on thermoplastic starch (TPS) were synthesized by reactive extrusion using a twin-screw extruder. Two strategies were evaluated to reduce the disadvantages of TPS for packaging applications. First, starch was chemically modified producing the reaction of native starch with chemical reagents that introduce new functional groups to reduce the water adsorption. And two, nano-fillers were incorporated into TPS in order to enhance the mechanical and barrier properties, driving to materials with improved performance/cost ratio. The synergistic strategies of chemical modification and incorporation of modified nanoclays were also effective to reduce the dependence of properties of TPS with the environment humidity and the evolution thereof over time, which influences the performance during the service life of the product.