Processing–properties–applications relationship of nanocomposites based on thermoplastic corn starch and talc

Abstract

Films based on thermoplastic corn starch (TPS) and talc nanoparticles were developed by melt mixing and thermo-compression. Films structure, optical and barrier properties, as well as thermal stability and water sorption behavior were studied. TPS structure resulted homogeneous and smooth. Talc laminar morphology and thermo-compression induced particle preferential orientation within the matrix. Good particle distribution and talc-TPS adhesion were evidenced. Nanometric thickness of mineral particles allowed obtaining translucent composite films, without significant color variation of TPS films. Talc addition at concentrations higher than 3% w/w led to an improvement on TPS barrier properties against water vapor and oxygen. It was also demonstrated that talc decreased water uptake of TPS films exposed to ambient conditions with relative humidity higher than 40%. In conclusion, films based on TPS and talc nanoparticles could be an alternative to develop biodegradable packages for food products with suitable final properties.