Synthesis of dodecyl phenol-based reactive nonionic surfactants and evaluation of their properties in emulsion pressure-sensitive adhesives

In this study, reactive nonionic surfactants were synthesized by reacting dodecylphenol ethoxylates (DPEs) with varying ethylene oxide chain lengths and vinyl acetic acid. These synthesized surfactants were employed in the production of pressure-sensitive adhesives (PSAs) via water-based emulsion polymerization, and their adhesive properties were evaluated to assess their potential as substitutes for traditional nonylphenol ethoxylate (NPE) surfactants, such as NPE-40, which is now classified as a regulated substance. The PSAs synthesized with the DPE-based reactive nonionic surfactants developed in this study exhibited superior adhesive properties compared to those prepared with the non-reactive surfactant NPE-40. Notably, the PSAs synthesized with DPE-10-based reactive nonionic surfactants demonstrated better or comparable peel strength and heat resistance than those prepared with NPE-40. Additionally, they performed comparably to, or even surpassed, the reactive alkyl ethoxylate surfactant ER-10, which consists only of alkyl chains and does not contain the aromatic functional group found in nonylphenol ethoxylate surfactants. Consequently, DPE-based reactive nonionic surfactants are identified as suitable alternatives to the usage-restricted NPE-40 surfactant and the reactive alkyl ethoxylate surfactant.