Modification of poly(styrene-co-divinylbenzene) resin by grafting on an aluminium selective ligand
Résumé
For use in the solid-phase extraction of aluminium, a polystyrene-co-divinylbenzene) commercial resin (Amberlite(R)) XAD-4) was modified by grafting on salicylic acid. Anchorage of this ligand was achieved via a ketone bridge formed by Friedel-Crafts acylation. Because of the insolubility of the resin in common organic solvents, the synthesis scheme was optimized on the monomeric entity, benzoyl chloride, so that the purity of products could be assessed by common analytical techniques (gas chromatography-mass spectrometry (GC-MS), NMR and FTIR) and the yields improved. NMR spectroscopy indicated that the Friedel-Crafts acylation was performed in the position Para to the methoxy group. The synthesis scheme was then applied to the resin activated by an acid chloride function. Different steps of the modification were characterized by FTIR and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The aluminium complexing capacity of the modified resin was evaluated and presence of complexed aluminium on the surface of the resin was assessed by scanning electron microscopy (SEM) and FTIR