High Barrier Nanocomposite Film with Accelerated Biodegradation by Clay Swelling Induced Fragmentation

Conventional biodegradable polymers such as poly(lactic acid) (PLA) are an attractive alternative to replace traditional nondegradable food packaging films which plague the environment. However, PLA has shown not be degradable in some environmentally relevant conditions, including within freshwater systems. Additionally, suffers from very poor barrier properties, could result spoilage. Compositing with clay been used improve properties according tortuous path theory. Here a synthetic, large aspect ratio Na-Hectorite is that may utterly delaminated organic solvent and composited by modification 18-crown-6 (18C6Hec), yielding castable, homogeneous nematic suspension. Upon drying, thermodynamics drive suspension toward segregation into sublayers of partially restacked 18C6Hec situ. This unique self-assembled nanostructure combines best two worlds: The remains high results 99.3% reduction oxygen permeability. film shows surprisingly resistance swelling at elevated humidity, but once soaked water, triggered, fragments drastically increases surface area 2500%. Accelerated degradation observed under controlled enzymatic conditions wastewater medium during CO2 evolution testing.