Dual function galactoglucomannan derivative for emulsion polymerization towards barrier coating applications

The growing demand for sustainable barrier coating solutions, driven by the circular bioeconomy and the urgent need to combat plastic pollution, has intensified the search for environmentally friendly alternatives to conventional plastic-based coatings. A key challenge in this field is the reliance on fossil-derived plastic substrates and the use of harmful ionic surfactants in emulsion systems, which are hazardous and toxic when released into aquatic ecosystems. In response to these challenges, this work explores the development of eco-friendly, bio-based latices derived from galactoglucomannan (GGM), a softwood-based hemicellulose, for barrier coating applications. GGM was chemically modified with allyl glycidyl ether (AGE), enabling its dual function as a non-ionic surfactant and as a co-monomer in the polymerisation process. Stable latices were successfully synthesized using a 1:1 ratio of modified GGM and butyl acrylate (BA) without the need for commercial ionic surfactants. Notably, the use of galactoglucomannan-derived surfactant significantly accelerates the polymerisation reaction, achieving a 90 % conversion yield within just 5 min. This rapid conversion not only improves process efficiency but also contributes to a reduction in the carbon footprint, as it minimizes energy consumption and eliminates the need for traditional surfactants. The resulting bio-based latices were cast into films and evaluated for their barrier properties, demonstrating an oxygen transmission rate of 10 cm ³/m ².day and a water vapour transmission rate of 80 g/m ².day. These promising results highlight the potential of galactoglucomannan as a sustainable and effective material for barrier coatings in packaging applications, offering a viable alternative to traditional, fossil-based plastic systems and supporting a more sustainable, circular bioeconomy.