Abstract
Polylactide (PLA) is viewed as a potential
material to replace synthetic plastics (e.g., poly(ethylene
terephthalate) (PET)) in food packaging, and there have
been a number of developments in this direction. However, for
PLA to be competitive in more demanding uses such as the
packaging of oxygen-sensitive foods, the oxygen permeability
coefficient (OP) needs to be reduced by a factor of ∼10. To
achieve this, a layer-by-layer (Lbl) approach was used to
assemble alternating layers of montmorillonite clay and
chitosan on extruded PLA film surfaces. When 70 bilayers
were applied, the OP was reduced by 99 and 96%, respectively, at 20 and 50% RH. These are, to our knowledge, the best
improvements in oxygen barrier properties ever reported for a PLA/clay-based film. The process of assembling such multilayer
structures was characterized using a quartz crystal microbalance with dissipation monitoring. Transmission electron microscopy
revealed a well-ordered laminar structure in the deposited multilayer coatings, and light transmittance results demonstrated the
high optical clarity of the coated PLA films.
Original language | English |
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Journal | Biomacromolecules |
Volume | 13 |
Issue number | 2 |
Pages (from-to) | 397-405 |
ISSN | 1525-7797 |
DOIs | |
Publication status | Published - 2012 |