Enhanced performance of acrylic latex laminating adhesives via novel 2-hydroxyethyl acrylate (HEA): optimized adhesion, thermal resistance, and long-term stability

Acrylic latex laminating adhesives (ALLAs) are widely used in packaging, textiles, and construction due to their strong adhesion, flexibility, and environmental compatibility. However, enhancing their mechanical strength, thermal resistance remains a key challenge. This challenge was overcome by the addition of functional monomer like 2-hydroxyethyl acrylate (HEA) which significantly improved the adhesive performance of ALLAs. This study developed ALLAs using a monomer-limited seeded semi-continuous emulsion polymerization, employing butyl acrylate (BA), methyl methacrylate (MMA), and HEA. The incorporation of HEA significantly improved the stability of latex, as well as the properties of resulting film and its adhesion strength. Furthermore, the findings of FTIR analysis confirmed the successful integration of HEA into the polymer backbone. The average latex particle size remained stable, but particle size distribution widened as HEA concentration increased from 0 to 0.5 wt%. Higher HEA content led to an increase in gel content, glass transition temperature (Tg), and molecular weights (Mn, Mw). Meanwhile, the water contact angle decreased, indicating improved hydrophilicity. The highest peel strength of 5.67 N/15 mm was observed at 0.3 wt% of HEA. Even at 70 °C, the film maintained a peel strength of 2.51 N/15 mm, ensuring strong adhesion under elevated temperatures. These results highlight the potential of HEA-modified ALLAs to improve durability and performance in high-temperature applications.