Biodegradable poly(vinyl alcohol)-based nanocomposite film reinforced with organophilic layered double hydroxides with potential packaging application

The continuously increasing plastic wastes and diminishing fossil resources have attracted global attention into research and development of biodegradable packaging materials. In the present study, organophilic layered double hydroxides (OLDH) intercalated with aliphatic long-chain molecules as reinforcing agents were incorporated into biodegradable poly(vinyl alcohol) (PVA) matrix by a solution casting method. FTIR, XRD and SEM were performed to analyze the structure of PVA/OLDH films. The OLDH nanosheets were well-dispersed in PVA matrix and formed strong interfacial interactions with the PVA chains, leading to remarkable improvements of optical property, mechanical performance, water vapor barrier property and thermal stability. At a loading of only 2% OLDH in PVA, we observed ~67% decrease in haze and ~66% increment in tensile strength in the composite film compared with pure PVA film. Furthermore, a 24.22% decrease in water vapor permeability (enhancement in water vapor barrier property) due to the addition of 0.5 wt% OLDH and enhanced thermal stability could be observed. These results revealed that the overall performance could be improved by introducing OLDH at very low loadings and that the PVA nanocomposite films have potential for future application in packaging films. Therefore, the use of high-performance PVA/OLDH nanocomposite films can evidently promote the application of biodegradable PVA materials in packaging industry.