Electrical properties of chelating copolymers and their metal complexes: binary chelating copolymers of styrene with organic acids

Abstract

Background

The emulsion polymerization of vinyl monomers has been extensively researched, but copolymerization with crotonic acid or cinnamic acid is relatively uncommon. These acids are capable of coordinating with other metal ions. Our previous research has focused on synthesizing and characterizing copolymers of butyl acrylate (BuA)/vinyl acetate (VAc) and styrene-BuA using emulsion techniques, specifically for paint applications. The current work aimed to synthesize and characterize three binary chelating copolymers of styrene with maleic, cinnamic, and crotonic acids. In addition, the prepared chelating copolymers were treated with water and soluble salts of copper and iron for complex formation. Additionally, the characterization and electrical properties of these copolymers were investigated.

Results

This article reports the synthesis of three binary copolymers of styrene with cinnamic, crotonic, and maleic acids via an emulsion polymerization process using a redox initiation system of potassium persulfate/glucose in the presence of sodium dodecyl benzene sulfonate as an emulsifier. The prepared emulsions of the copolymers were precipitated and purified using Soxhlet extraction in a mixture of n-hexane and toluene. Spectroscopic measurements, including Fourier transform infrared (FTIR), proton nuclear magnetic resonance (¹H-NMR), and powder X-ray diffraction (PXRD), in addition to thermal analysis methods like thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were employed to characterize the copolymers that were synthesized. The metal complexes of the chelating copolymers were prepared by treatment with soluble metal salts of Co(II), Cu(II), and Fe(III), purified, and characterized via IR, PXRD, TGA, and DSC. The semiconducting properties of the chelating polymers and their metal complexes were demonstrated through conductivity measurements taken at room temperature. The conductivity values ranged from 10⁻³ to 10⁻⁶ Ω⁻¹ cm⁻¹.

Conclusion

The research underscores the significance of the electrical characteristics of chelating copolymers and their metal complexes, particularly focusing on styrene-based binary chelating copolymers, in driving advancements in technology, science, and economic development.