Hybrid poly(lactic acid)/nanocellulose/nanoclay composites with synergistically enhanced barrier properties and improved thermomechanical resistance

Poly(lactic acid) ( PLA )‐based hybrid nanocomposites ( PLA , nanoclay and nanocellulose) were prepared by reinforcing neat PLA with commercially available nanoclay (Cloisite C30B ) and nanocellulose, in the form of either partially acetylated cellulose nanofibres ( CNFs ) or nanocrystalline cellulose. Composites with 1 or 5 wt% of nanocellulose, in combination with 1, 3 and 5 wt% of nanoclay, were prepared, and their barrier properties were investigated. It was found that the combination of clay and nanocellulose clearly resulted in synergistic behaviour in terms of the oxygen transmission rate ( OTR ) through a reduction of up to 90% in OTR and a further reduction in the water vapour transmission rate of up to 76%. In addition, the nanocomposite films showed improved thermomechanical resistance and improved crystallisation kinetics while maintaining high film transparency. This makes the hybrid PLA / CNF / C30B nanocomposites a very promising material for food packaging applications.