Performance of poly(styrene-co-divinylbenzene) functionalized with different aminophosphonate pendant groups, in the removal of phenolic compounds from aqueous solutions

In the present work, we describe the synthesis and characterization of styrene-6.7 %-divinylbenzene copolymers functionalized with aminophosphonate groups by "one-pot" reactions. Different aminophosphonate groups were grafted on the copolymer with the aim of obtaining adsorbents for removal of phenolic compounds from aqueous solutions. Adsorption experiments were carried out in batch system. The phenolic compounds studied were phenol and 2,4,6-trimethyl-phenol. The best adsorption capacity was observed in the case of polymeric adsorbents functionalized with aminophosphonate groups in para-position of the aromatic nucleus for both phenol and 2,4,6-trimethyl-phenol. In comparison, the copolymers with the functional groups in ortho-position and respectively in meta-position were slightly less efficient. The differences in adsorption efficiency may be explained taking into account the structure of the adsorption active centers. The possible explanation is that the active functional groups responsible for the adsorption process, grafted in ortho-or meta-position could be affected by possible steric hindrance effects. The difference between the adsorption capacities of the polymers of the same series, are rather small and depending on the nature of the radical found in the structure of the aminophosphonate: isopropylamine or isobuthylamine.