AbstractThe preparation and characterization of poly(methyl methacrylate-ethylene glycol dimethacrylate), (poly(MMA-EGDMA)) polymer for erythrosine adsorption has been investigated. Erythrosine is a synthetic red dye used to color food. Water-soluble acid dyes have caused serious water pollution. Poly(MMA-EGDMA) polymer showed better adsorption performance for erythrosine at acidic region and at 30°C. The adsorption process had also been verified by Langmuir and Freundlich adsorption isotherms at 30, 40, and 50°C. Free energy of adsorption (∆G°), enthalpy (∆H°), and entropy (∆S°) changes were calculated to predict the nature of adsorption. The estimated value for ∆G° was calculated as −125.6 kJ/mol at 303 K (30°C). The estimated value for ∆H° was found as −60.69 kJ/mol at 303 K. The negative value for ∆H° indicated that the adsorption of erythrosine on poly(MMA-EGDMA) polymer was an exothermic process.