Active bilayer films of thermoplastic starch and polycaprolactone obtained by compression molding

Abstract

[EN] Bilayer films consisting of one layer of PCL with either one of thermoplastic starch (S) or one of thermo-plastic starch with 5% PCL (S95) were obtained by compression molding. Before compression, aqueoussolutions of ascorbic acid or potassium sorbate were sprayed onto the S or S95 layers in order to plas-ticize them and favor layer adhesion. S95 films formed bilayers with PCL with very good adhesion andgood mechanical performance, especially when potassium sorbate was added at the interface. All bilayersenhanced their barrier properties to water vapour (up to 96% compared to net starch films) and oxygen(up to 99% compared to PCL pure). Bilayers consisting of PCL and starch containing 5% PCL, with potas-sium sorbate at the interface, showed the best mechanical and barrier properties and interfacial adhesionwhile having active properties, associated with the antimicrobial action of potassium sorbate.