Bio-based polyHIPEs from eugenol-derived methacrylates: morphology and antibacterial activity

A bio-based methacrylate monomer, eugenyl methacrylate (EMA), was synthesised from eugenol and used to prepare highly porous polyHIPE monoliths containing up to 80 mol% EMA. The effect of crosslinker structure was investigated using ethylene glycol dimethacrylate (EGDMA) and 1,6-hexanediol diacrylate (1,6-HDDA), and the resulting networks were characterised by FTIR spectroscopy, elemental analysis, scanning electron microscopy, nitrogen sorption analysis and thermogravimetric analysis. Crosslinker rigidity strongly influenced pore architecture. EGDMA produced larger pores (approx. 18–30 μm) with fewer interconnecting pores and higher specific surface areas (up to about 10 m 2 ⋅g −1 ), whereas 1,6-HDDA yielded smaller pores (approx. 7–15 μm), more interconnected structures, and lower specific surface areas (approx. 2–4 m 2 ⋅g −1 ). Both systems accommodated high EMA content while retaining structural integrity. Post-polymerisation modification was performed via a thiol-ene click reaction using a multifunctional thiol reagent. Elemental analysis confirmed its incorporation into the polymer network, resulting in a significant increase in specific surface area. The antibacterial properties of EMA and the corresponding polymer were investigated against Escherichia coli . Modifying eugenol into EMA does not compromise its antibacterial activity, which is further retained in the polymer material.