Barrier Properties and Crystalline Structure of Biowax‐Containing Water‐Based Polymer Dispersions Under Different Processing Conditions

In the food supply chain, packaging protects and preserves the food. From the sustainability standpoint, fiber materials are favored. However, these materials have insufficient barrier properties. Thus, fossil‐based materials are preferred, but more biocompatible solutions are needed due to current legislation and sustainable development goals. Water‐based polymer dispersions combined with biowaxes offer novel solutions to improve recyclability compared to traditional extrusion or lamination methods. In this study, the barrier properties and the micro‐ and nanoscale structural features of variously processed polyacrylate dispersions combined with commercially available biowax dispersions were systematically characterized and compared. The structural differences under various mixing and drying methods were studied. Enhanced barrier performance, including water and water vapor resistance, combined with favorable nanostructural properties (high lamellar order and an orthorhombic crystalline phase), was observed when the biowax was directly mixed with the dispersion and dried by infrared or air. The water vapor transmission rate decreased by 38% (±10%) and 56% (±11%) in these samples. This study provides key nanoscale structural information combined with barrier properties of the coatings. These findings help to optimize novel coating solutions and processes for more sustainable fiber‐based food packaging materials on the industrial scale.