Comparative performance and barrier properties of biodegradable thermoplastics and nanobiocomposites versus PET for food packaging applications

This article reports on preliminary studies of several comparative packaging properties between polyethylene terephthalate (PET) packaging films and biodegradable biopolymers such as polycarpolactone (PCL), polylacticacid (PLA), amorphous PLA (aPLA), and polyhydroxyalcanoates copolymer with 8 mol% valeriate (PHBV) and of some nanobiocomposites, in terms of thermal and retorting resistance (thermal humid processes) and oxygen, water vapor, aroma, and solvent barrier by means of time-resolved synchrotron radiation, FT-IR and direct permeation methods. This work suggests that while PHBV can easily withstand retorting and shows excellent water and aroma (limonene and linalool) barriers compared with PET, its solvent resistance (toluene and ethanol) and oxygen barrier properties are poorer. First, trials with compression molded food contact complying nanobiocomposites of PCL and aPLA show enhanced oxygen barrier but are not sufficient, as yet, to outperform high-oxygen-barrier grades of PET film.