Enhancing the water vapor barrier of eco-friendly, emulsion-coated paper via a bilayer-like structure design

Abstract

To further improve the water vapor barrier of paper packaging materials, eco-friendly, polyvinyl alcohol (PVA)/glycerol tristearate (GTS) emulsions were prepared as surface coatings. The hydrophilic hydroxyl groups within the PVA chains were consumed through a crosslinking reaction to improve water resistance. Introducing the hydrophobic GTS phase into the crosslinked matrix led to the formation of a bilayer-like structure, which could be tuned by changing the GTS content and the drying temperature. The microstructural evolution was revealed via scanning electron microscopy (SEM) and atomic force microscopy (AFM). Ultimately, the water vapor transmission rate (WVTR) of the coated paper was as low as 187 g/m2/24 h, which was 85.74% lower than the base paper. The key objective of this work was to develop an eco-friendly paper coating material with a good water vapor barrier for packaging applications.