Synthesis, characterization, and antibacterial activities of novel N-halamine copolymers Ying Chen Æ Li Wang Æ Haojie Yu Æ Quan Shi Æ Xiaochen Dong Received: 31 October 2005 / Accepted: 17 February 2006 / Published online: 31 January 2007 Ó Springer Science+Business Media, LLC 2007 Abstract The synthesis and antibacterial properties of N-halamine copolymers are reported in this paper. 3-(4¢-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) monomer and its copolymers with n-butyl methacry- late (BMA) were prepared under mild conditions. The effects of monomer feeds on the composition of the final copolymers and reaction conversion were inves- tigated. It was found that VBDMH had higher reac- tivities than BMA in the copolymerization reactions and the reactivity ratios of VBDMH and BMA were calculated to be 8.91 and 0.42, respectively, according to the Fineman–Ross equation in the preparation of PBMA-co-VBDMH. Two chlorination methods were applied and compared in the process of polymers chlorination. After chlorination by tert-butyl hypochlo- rite, the polymers provided powerful antibacterial activities against Escherichia coli (E. coli). The surface morphologies of the chlorinated polymer films used in antibacterial assessment were observed by scanning electron microscope. The copolymers before and after chlorination were characterized with fourier transform infrared (FTIR) and 1 H-nuclear magnetic resonance ( 1 H-NMR). Their thermal properties were analyzed with thermogravimetric analysis (TGA) studies. Introduction With the development of the society, people are more care about the health nowadays and many diseases are caused by micro-organisms exist on material surface. The antibacterial modification of material surfaces is of great importance. Consequently, biocidal polymer materials have received much attention in recent years [1, 2]. Currently there are several sorts of antibacterial polymers such as polymers containing heavy metal cations, pyridinium and quaternary ammonium salt polymers, and N-halamine polymeric biocides, among which, N-halamine polymeric biocides have shown to be disinfectants which provide almost instant and total kill of a wide range of micro-organisms [3, 4]. In addition, their N-halamine structures possess several useful features including good stability for long-term use and storage over a wide temperature range and ability to be regenerated in a chlorine solution repeat- edly [5–7]. Researchers have synthesized polymeric N-halamines through the chemical incorporation of cyclic amines into polystyrene or cellulose-contain- ing fabrics and halogenation of the resultant polymers [8, 9]. Those novel polymers were proven biocidal, and their antibacterial activities were durable and regener- able. Sun et al. [10] synthesized monomer of VBDMH and copolymerized it with acrylonitrile, vinyl acetate, and methyl methacrylate, respectively. After chlorina- tion, these copolymers exhibited powerful antibacterial activities. Till now, although there have been some important researches on N-halamine polymers [8, 10–12], types of antibacterial N-halamine polymers are still limited. Antibacterial mechanism and relationship between structure and antibacterial activity are still uncertain. Therefore, there is a need to continue Y. Chen  L. Wang (&)  H. Yu  Q. Shi  X. Dong State Key Laboratory of Polymer Reaction Engineering, College of Materials Science and Chemical Engineering, Zhejiang University, Hangzhou 310027, China e-mail: opl_wl@dial.zju.edu.cn J Mater Sci (2007) 42:4018–4024 DOI 10.1007/s10853-006-1412-x 123