Synthesis and Characterization of Polythioamides from Elemental Sulfur for Efficient Hg(II) Adsorption

A metal-free multicomponent polymerization (MCP) method was developed for synthesizing sulfur-containing polythioamides, using elemental sulfur, dicarboxylic acids, and diamines as monomers. This approach offers a versatile strategy for producing polythioamides with excellent thermal stability and high mechanical strength. The synthesized polymers demonstrated a maximum Hg(II) adsorption capacity of 187 mg·g−1, with adsorption efficiencies exceeding 90% for most polymers. Both aliphatic and aromatic polythioamides showed similar high adsorption performance, indicating the universal applicability of this synthesis method. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed the strong interaction between Hg(II) ions and the sulfur-containing thioamide groups. These results highlight the potential of MCP-based polythioamides as efficient adsorbents for mercury removal, with promising applications in environmental remediation.