Efficient Gas Barrier and Antibacterial Properties of Poly(lactic acid) Nanocomposites: Functionalization with Phytic Acid–Cu(II) Loaded Layered Clay

Abstract

Poly(lactic acid) (PLA) represents one of the most promising and attractive bio-based polymers for green packaging. However, toughness, gas barrier and antibacterial properties of pure PLA films cannot compete with those of traditional petroleum-based active packaging plastics. To fill this gap, utilization of excellent chelating properties of phytic acid (PA), functionalized layered double hydroxides (LDHs@PA-Cu(II)) was firstly synthetized via facile deposition and chelation of one-step assembled PA-Cu(II) coordination compounds on the surface of layered clay. Furthermore, LDHs@PA-Cu(II)/PLA nanocomposites were prepared by blending LDHs@PA-Cu(II) and pure PLA via solution casting evaporation process. After adding only 1 wt % LDHs@PA-Cu(II), elongation at break and tensile strength increase by 53.0% and 18.9%, respectively, and the oxygen relative permeability decreases by 28.0%. Due to the strong interface interaction and heterogenous nucleation, the reinforcement effect of LDHs@PA-Cu(II) at low loadings is remarkable. Meanwhile, owing to the antibacterial activity of PA-Cu(II) coatings, the antibacterial rate (against Escherichia coli) of LDHs@PA-Cu(II) exceeds 99.99%. Furthermore, the corresponding LDHs@PA-Cu(II)/PLA nanocomposites also show outstanding antibacterial properties, which will be a promising candidate for active packaging application.

High oxygen barrier property of polyethylene composite films with bilayer polyvinyl alcohol coating for emergency foods in high‐humidity environments

“…Thermogravimetric analyzer (TGA, Q500, Tzero, USA) was used to characterize the thermal stability of coated PE composite films. All the tests were carried out in a nitrogen environment with an equilibrium protection flow rate of 40 cm 3 /min and a sample gas flow rate of 60 cm 3 /min 22 . The haze of the coated PE composite films was measured by a light transmission/haze tester (WGT‐S, Shanghai Jinke, China).…”

“…All the tests were carried out in a nitrogen environment with an equilibrium protection flow rate of 40 cm 3 /min and a sample gas flow rate of 60 cm 3 /min. 22 The haze of the coated PE composite films was measured by a light transmission/haze tester (WGT-S, Shanghai Jinke, China). The transmittance of composite films at 800 nm was determined by a UV spectrophotometer (UV-1800, SHIMADZU, Japan) with air as blank.…”

Development of catechol‐functionalized chitosan/poly(vinyl alcohol) nanocomposite films incorporated with dual network coated layered clay for active packaging applications

“…Unlike other polymer matrix (such as poly(ε-caprolactone), poly(lactic acid), etc. ), 22,29 the addition of LDHs@TA-Ti does not ultimately improve the χ of C-CS/PVA composites, although it plays a role in the heterogeneous nucleation.…”

Trends in Layered Double Hydroxides‐Based Advanced Nanocomposites: Recent Progress and Latest Advancements

“…[ 144c ] In several cases, these polymeric matrices were encapsulated with transition metals, such as silver [ 243 ] and copper. [ 244 ] due to the outstanding antibacterial efficacy and the gas/vapor barrier property. As the gas barrier materials, in a case, (XAl‐LDH/PAA) n ‐CO 2 was designed to achieve chemical adsorption of CO 2 in the interlayers of LDHs.…”