Moving Toward Paperization of Packaging Industry: Use of Laponite and Montmorillonite Nanoclays for Recyclable and Biodegradable High-Barrier Paper

Plastic packaging raises environmental concerns due to the release of microplastics, which has led to increasing interest in paper as an alternative to plastic packaging. However, creating paper that is both recyclable and biodegradable (no microplastic formation over its lifecycle) and still providing the needed oxygen barrier has been a challenging task to achieve. Reported herein is the use of biodegradable poly-(vinyl alcohol) (PVOH) for paper coating, incorporating different nanoclays (laponite and montmorillonite) at various concentrations and assessing their barrier properties. Analysis of the gas, moisture, thermal, and mechanical properties of the samples showed enhanced performance, particularly for laponite-based samples. At a temperature of 23 °C and 50% relative humidity, the oxygen permeability coefficient (OP) of the best sample was 0.875 ± 0.02 cm3·mm/m2·day, 9-fold lower than that of polyethylene terephthalate (PET) film (11.68 ± 0.41 cm3·mm/m2·day) of 0.058 mm thickness. The coated paper is also repulpable and recyclable per the FBA protocol. Overall, this work offers an opportunity to develop alternative packaging materials with good oxygen barriers and mechanical properties without releasing microplastics or perfluoroalkyl and polyfluoroalkyl substances (PFAS) into the environment.