Synthesis and modification of amine-terminated maleic anhydride‑butyl acrylate copolymer and investigation of adsorption properties for cadmium (II) ions (Cd2+)

In this study, a maleic anhydride‑butyl acrylate copolymer (MA-BA) was synthesized using maleic anhydride (MA) and butyl acrylate (BA) monomers. The synthesis was carried out in methyl ethyl ketone by benzoyl peroxide as the initiator at 70 °C. Secondly, the MA-BA copolymer was chemically modified with ethylenediamine and abbreviated as NH2MA-BA. The copolymer and its modified structure were analyzed spectroscopically by FT-IR, thermally by Thermo Gravimetry (TGA) and by Differential Scanning Calorimetry (DSC). Solubility tests of both structures were performed. Then, the adsorption of cadmium ions (Cd2+) by the modified copolymer (NH2MA-BA) was studied. The copolymer and its modified structure were synthesized successfully, and this was proven by their FTIR spectra. The (MA-BA) copolymer is soluble in common organic solvents but (NH2MA-BA) is not due to cross-linking. The DSC and DTA results showed that chemical modification improved the structure thermally. It was shown that the Freundlich model was the best explanation for the adsorption type in correspondence with the experimental plots, and the modified copolymer is a good candidate for Cd2+ adsorption.