The effect of organo‐modified silicate nanolayers on the oxygen and water vapor barrier properties of poly(lactic acid)

For improving the oxygen and water vapor barrier properties of poly(lactic acid) (PLA), a new series of PLA‐based nanocomposite films containing an organoclay (OC) and a hydrogel were prepared via the solvent casting method. The synthesized hydrogel was used in a PLA system combined with and without the reactive organo‐modified clay. Montmorillonite and the protonated form of SABO®STAB UV 94 were used to prepare the OC via an ion‐exchange reaction. The modification of silicate layers was investigated by FTIR, XRD, and TGA techniques. The char residue of the OC obtained was 28% lower than that of the neat montmorillonite, which indicated the presence of SABO in the silicate layer structure. In the presence of the OC, the hydrogel showed a synergistic effect to enhance the barrier properties of PLA. The water vapor permeability decreased from 0.243 to 0.224 g/m2·24 hr in PLA/hydrogel‐OC nanocomposite containing 3 mass% each of the hydrogel and OC (PSH 6) compared to the neat PLA. Also, the oxygen permeability of PSH 6 was 37% lower than that of the neat PLA.