Design and Development of Eco-friendly Packaging System Utilizing Lignin Based Hydrogel Coated Biodegradable Paper

Abstract

A lignin based hydrogel was synthesized by physically cross-linking polyvinyl alcohol (PVA), chitosan (Ch) and lignin (Lgn) precursors. The prepared hydrogel was subjected to the cellulosic paper base as a biocoating. The interactions among the hydrogel precursors and effect of hydrogel on the crystalline behavior of hydrogel was evaluated using FTIR and XRD and the overall effect of hydrogel on the mechanical strength and barrier properties of the newly developed materials were investigated through tear index, tensile strength, puncture resistance, Cobb tests for water and oil and water contact angle measurements of uncoated and biocoated paper surfaces. The analysis of strength parameters revealed that the prepared biocoating improved the mechanical properties of the material by 40% as compared to the uncoated paper. The water contact angle analysis confirmed that the addition of lignin and chitosan to the PVA matrix sufficiently improved the hydrophobicity of paper surface resulting an improved resistance to water adsorption. The air, moisture and oil barrier properties again suggested that and an increase in the lignin concentration improved the barrier properties of the paper. The biodegradability of the prepared paper samples were investigated using compostability test. A customized soil burial test was developed and the extent of biodegradability was evaluated over a time period of 30 days. The research underscores that the prepared PVA/chitosan/lignin based biocoating has a great potential to not only provide good mechanical and barrier properties but also has a potential to replace synthetic packaging materials for sustainable and eco-friendly biobased packaging material.