Studies of Melamine−Formaldehyde Resins by Sorption from Gas and Liquid Phases

Three types of mesoporous melamine−formaldehyde resins are synthesized in the process of polymerization in the presence of fumed silica as an inorganic template. The obtained sorbents have different pore structures and surface properties. The process of adsorption of nitrogen from the gas phase and sorption of organic substances from dilute aqueous solutions is used to study the character of polymer porous structures and surface properties. The thermogravimetric measurements are applied to study the swelling process in water. The structure characteristics of melamine−formaldehyde resins are determined from nitrogen adsorption/desorption isotherms: BET specific surface area; the total pore volume; the external surface area; the mesopore volume. The isotherms of sorption of various organic substances from aqueous phase are measured for a wide range of solution concentrations by using the static method. The liquid sorption data are analyzed to study the effect of polymer structure and surface properties on sorption processes.