Catalyst-Free Synthesis of Antibacterial Poly(Ethylene Succinate) with Gemini Quaternary Ammonium Salts

Abstract

Polyesters are widely used in textiles, packaging, and biomedical materials due to their excellent mechanical properties, chemical stability, and cost-effectiveness. However, synthesizing antibacterial polyesters remains challenging. Traditional methods rely on metal catalysts, risking cytotoxic metal residues, while conventional polyesters lack intrinsic antibacterial activity and require additives. Inorganic antibacterial agents may cause toxicity, and organic antibacterial agents often degrade during high-temperature processing. To overcome these issues, this study developed thermally stable, polymerizable gemini quaternary ammonium (GQA) salts as antibacterial comonomers. Using catalyst-free melt polycondensation, an antibacterial poly(ethylene succinate) (PES) was synthesized, with antibacterial groups covalently bonded to the polymer chain. The resulting material maintained thermal and mechanical properties similar to pure PES. Notably, just 500 ppm of GQA comonomer achieved nearly 100% antibacterial efficacy against Staphylococcus aureus and Escherichia coli. This metal-free, scalable approach enables high-safety antibacterial polyesters for critical applications.

Keywords: Antibacterial activity, Catalyst-free synthesis, Gemini quaternary ammonium salt, Melt polycondensation, Polyester