Oxygen and water vapor barrier properties of polyvinyl alcohol and zein bilayer-coated paper

As reported herein, a bilayer coating approach using poly(vinyl alcohol) (PVOH) and zein is employed to enhance the water vapor and oxygen barrier properties of paper materials. The coating was applied onto three different types of paper substrates to study the general applicability of this approach. The bilayer-coated paper samples exhibited a reduction of up to 65% in their water vapor transmission rate in comparison to the corresponding uncoated paper substrates at 23 degrees C and 50% relative humidity. In addition, the bilayer-coated paper samples showed at least a 40-fold decrease in oxygen transmission rate from that of the uncoated paper samples. In addition, the coated paper showed excellent thermal stability and mechanical properties. Scanning electron microscopy confirmed that the obtained coated paper has a smooth texture without pores. Pulp was recovered from the coated paper by washing with water/ethanol. Thus, this work provides a unique coated paper with excellent barrier properties and therefore has the potential for real-world application as an alternative to single-use plastics.