Synthesis and biocidal activities of polymer. IV. Antibacterial activity and hydrolysis of polymers containing diphenyl ether

The antibacterial monomer, 2,4,4′-trichloro-2′-acryloyloxydiphenyl ether (AcDP) was synthesized from 2,4,4′-trichloro-2′-hydroxydiphenyl ether (DP) and acryloyl chloride in the presence of dry THF at 20°C. Copolymers of AcDP with acrylic acid [poly(AcDP-co-AA)] or 2-hydroxyethyl methacrylate [poly(AcDP-co-HEMA)] were synthesized using BPO as a thermal initiator at 70°C. The synthesized poly(AcDP-co-AA) and poly(AcDP-co-HEMA) were identified by IR and 1H-NMR spectra. The monomer reactivity ratios, r1 (AcDP) and r2 (AA), determined by the Kelen–Tüdös method, were 0.21 and 1.28, respectively. The number average molecular weights of poly(AcDP-co-AA) and poly(AcDP-co-HEMA) were 2400 and 3000, respectively. The glass transition temperatures of poly(AcDP-co-AA) and poly(AcDP-co-HEMA) were 87 and 50°C, respectively. The rate of hydrolysis decreased in the order of poly(AcDP-co-AA) > AcDP > poly(AcDP-co-HEMA) > poly(AcDP). The antibacterial activities of poly(AcDP-co-AA) and poly(AcDP-co-HEMA) were studied against Staphylococcus aureus by the shake flask test. The antibacterial activity of poly(AcDP-co-AA) was higher than that of poly(AcDP-co-HEMA). The trend of magnitude of the antibacterial activities for copolymers containing the AcDP unit was in agreement with that of the rate of hydrolysis for the copolymers.