The bactericidal 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 triethylamine in dry THF at 20 degrees C. The synthesized AcDP was identified by IR, H-1-NMR, and GC-MS spectra. The homopolymer of AcDP was obtained using BPO as an initiator in toluene at 70 degrees C. Copolymer of AcDP and styrene (St) was synthesized with a free radical initiator at 70 degrees C. Poly (AcDP) and poly (AcDP-co-St) were identified by IR and H-1-NMR spectra. The maximum weight average molecular weights (Mw) of poly (AcDP) and poly (AcDP-co-St) s were 4100 and 11600, respectively. The monomer reactivity ratios, r(1) (AcDP) and r(2) (St), determined by the Kelen-Tudos method, were 0.16 and 0.33, respectively. The glass transition temperature and decomposition temperature of poly (AcDP) were 73.4 degrees C and 348 degrees C, respectively. The bactericidal activities of AcDP, poly (AcDP), and poly (AcDP-co-St) were studied using agar dish test. The bactericidal activities of AcDP and its polymers as well as DP against Pseudomonas aeruginosa were very excellent compared to those of control polymers such as poly (St) and poly (ethylene-co-vinyl acetate). The bactericidal activities were decreased in the order DP > AcDP > poly (AcDP) > poly (AcDP-co-St) against Pseudomonas aeruginosa.