A review of recent development in preparation and modification of waterborne polyurethanes and their application in waterborne inks for plastic packaging printing

Abstract

In recent years, the ongoing development of the waterborne polyurethane (WPU) industry has resulted in its widespread application in adhesives, waterborne coatings, waterborne inks, and other sectors. To meet the required specifications of WPU, researchers have developed various modification techniques aimed at improving WPU performance. This paper provides an overview of the preparation principles and methods for WPU. It subsequently offers a comprehensive review of modification methods employed to improve WPU properties, including water resistance, heat resistance, mechanical properties, adhesion, and antimicrobial properties. These methods are broadly categorized into six types: crosslinking modification, acrylic modification, epoxy modification, organosilicon modification, organofluorine modification, and nanoparticle modification. Furthermore, the progress of WPU research in water-based inks for food and pharmaceutical plastic packaging printing has been analyzed. Additionally, the modification methods of WPU and the limitations of WPU in aqueous inks for plastic packaging printing were identified. Finally, the future development of WPU in aqueous inks for packaging printing was discussed. We believe that these research advancements will contribute to the enhancement of environmental safety for WPUs, address environmental pollution issues, and promote the use of eco-friendly water-based inks.