Preparation and Characterization of Poly(2,2-dimethyl-1,3-propylene oxalate) Polymer and the Study of its Metal Uptake Behavior Toward Pb(II), Cd(II), and Hg(II) Ions

Abstract

Poly(2,2-dimethyl-1,3-propylene oxalate) was synthesized from oxalyl chloride and 2,2-dimethyl-1,3-propane diol. The polymer was characterized by inherent viscosity, FT-IR, XRD, SEM, ¹H-NMR, ¹³C-NMR, DSC, and TGA. The polymer uptake behavior towards Pb(II), Cd(II), and Hg(II) ions was studied by the batch equilibrium technique as a function of pH and contact time. The adsorption isotherms of metal ions were also investigated. Column experiments were used to determine the loading capacity and study desorption of metal ions. The polymer showed high metal-ion uptake capacity towards Pb(II), but moderate capacity towards Cd(II) and Hg(II) ions. Interestingly, the polymer was found to be highly selective for Pb(II) ions at pH 5 and 25°C. The metal ion uptake properties of the polymer show fittings for both Langmuir's and Freundlich equations. The metal-bound polymer was regenerated by treatment with 1 M HNO₃. Therefore, it may be employed for the removal of heavy metal pollutants in environmental and industrial applications.