Abstract: The adsorption separation and thermodynamic behavior of 2,4-diaminotoluene and 2,6-diaminotoluene on macropore acrylic acid weak acid cation exchange resin(D151 resin), which was selected from ten resins, were investigated. The adsorption isotherms of 2,4-diaminotoluene and 2,6-diaminotoluene were measured. The result showed that the adsorption isotherm curves of 2,4-diaminotoluene and 2,6-diaminotoluene on D151 resin fitted Freundlich adsorption isotherm better than Langmuir with the correlation coefficient larger than 0.99. The study of thermodynamics showed that when the initial concentration of 2,4-diaminotoluene were 60～80 g/L within 293～313 K, the adsorption ΔH was -4.3490～-5.7558 kJ/mol, ΔG was -0.2911～-1.0346 kJ/mol, ΔS was -12.965～-16.150 J/(mol·K); and when the initial concentration of 2,6-diaminotoluene were 60～80 g/L within 293～313 K, adsorption ΔH was -2.9645～-3.6054 kJ/mol, ΔG was -0.1610～-0.6384 kJ/mol, and ΔS was -7.939～-11.005 J/(mol·K). The results show that the concentration of 2,6-diaminotoluene can be enriched from 20% to 99.93%, and 2,4-diaminotoluene can be increased from 80% to 99.42% with the dynamic adsorption separation.

Key words: D151resin, diaminotoluene, adsorption separation