The aim of the study was the development of a multi-functional, high-performance, fully biodegradable multi-layer polylactic acid (PLA) film for food packaging applications. In particular, sealable multi-layer PLA/clay nanocomposite systems with different layouts in terms of composition and relative thickness of the layers, all consisting of a PLA/clay nanocomposite layer between two pure PLA layers for direct food contact, were designed and produced by blown film co-extrusion. The films which were obtained were analysed for their morphology, functional properties and lactic acid specific migration in 50% ethanol. The results showed that, with respect to the unfilled multi-layer system, taken as reference, the nanocomposite ones had significant improvements, up to ca. 40%, in their barrier to oxygen and tensile strength values, and resulted in being more easily sealable over a wide heat sealing temperature range (80°C-100°C) with higher seal strength. Moreover, all films had lactic acid migration values always well below the former generic overall migration limit of 60 mg/kg food (10 mg/dm(2)) of Regulation EU 10/2011 (deleted by the amending Regulation EU 2016/1416), even if their morphology was strongly modified during the migration tests due to the strong swelling action of the used simulant (simulant D1 = 50% ethanol (aq.) (v:v)) towards PLA.
Performance properties, lactic acid specific migration and swelling by simulant of biodegradable poly(lactic acid)/nanoclay multilayer films for food packaging
SCARFATO, Paola;DI MAIO, Luciano;INCARNATO, Loredana
2017
Abstract
The aim of the study was the development of a multi-functional, high-performance, fully biodegradable multi-layer polylactic acid (PLA) film for food packaging applications. In particular, sealable multi-layer PLA/clay nanocomposite systems with different layouts in terms of composition and relative thickness of the layers, all consisting of a PLA/clay nanocomposite layer between two pure PLA layers for direct food contact, were designed and produced by blown film co-extrusion. The films which were obtained were analysed for their morphology, functional properties and lactic acid specific migration in 50% ethanol. The results showed that, with respect to the unfilled multi-layer system, taken as reference, the nanocomposite ones had significant improvements, up to ca. 40%, in their barrier to oxygen and tensile strength values, and resulted in being more easily sealable over a wide heat sealing temperature range (80°C-100°C) with higher seal strength. Moreover, all films had lactic acid migration values always well below the former generic overall migration limit of 60 mg/kg food (10 mg/dm(2)) of Regulation EU 10/2011 (deleted by the amending Regulation EU 2016/1416), even if their morphology was strongly modified during the migration tests due to the strong swelling action of the used simulant (simulant D1 = 50% ethanol (aq.) (v:v)) towards PLA.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
