Reactive extrusion for the production of starch-based biopackaging

Abstract

Reactive extrusion (REx) combines mass and heat transport operations, which together with simultaneous chemical reactions taking place inside the extruder, modify the properties of existing polymers or generate new ones. The combination of chemical reactions and transport phenomena in an extruder provides an invaluable window of opportunity for the compatibilization of synthetic resins and biopolymers such as starch, or the compatibilization of synthetic resins and natural fillers. The oxidized starch interacts more strongly with the plasticizer, thus enabling the production of thermoformable materials for biopackaging. Starch is a polysaccharide produced by mostly higher order plants as a means of storing energy. The main problem encountered when mixing starch with polylactic acid (PLA) is the poor interfacial adhesion between them, resulting from the hydrophilic nature of the starch and the hydrophobicity of the PLA. Extruding corn starch/microcrystalline cellulose mixtures in the presence or absence of plasticizers has been done by REx conditions to produce edible films.