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This paper describes for the first time the combination of a polymerizable surfactant, sodium 2-acrylamido-dodecane sulfonate (NaAMC12S), and a hydrophobic monomer to prepare water-soluble associating polymer via a new micellar process. In this method, the hydrophobic monomer, N-dodecylacrylamide (C12AM) or N,N-didodecylacrylamide (DiC12AM), was first solubilized within NaAMC12S micelles, whereas the hydrophilic monomer acrylamide (AM) was dissolved in the aqueous continuous medium. The micellar copolymerization, therefore, resulted in a ternary hydrophobic association polyacrylamide (HAPAM), namely, C12AM/NaAMC12S/AM or DiC12AM/ NaAMC12S/AM. The chemical structures of these ternary copolymers were characterized with Fourier transform infrared (FTIR) spectroscopy, and their hydrophobic associative behavior as well as the relationship between microstructure and hydrophobic associative property was studied by a combination of the fluorescence probe technique and viscosimetry. The experimental result shows, with the presented polymerizable surfactant or surface-active monomer NaAMC12S, the micellar copolymerization of AM and hydrophobic monomer can be favorably realized. In addition, the surface-active monomer can be incorporated into the polymer backbone to result in the ternary copolymers, which show a much stronger hydrophobic associative property in comparison with the binary copolymer obtained in the conventional micellar copolymerization system with common surfactants. More importantly, this new micellar copolymerization system is simple because the complicated process to remove the surfactant is avoided. We found that the hydrophobic associative property of the obtained ternary HAPAM is strongly affected by the hydrophobe content and the length of hydrophobic microblocks in the polymer backbone.

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Quaternized polyethyleneimine (QPEI) was prepared via two types of macromolecular reactions, tertiary amination reaction and quaterization, and its chemical structure was characterized using infrared and UV spectroscopy. In this paper, the antibacterial properties of QPEI were mainly investigated by using Escherichia coli as model bacterium and with the colony count method. The effects of the cationic degree and pH value of the medium on the antibacterial properties of QPEI were examined. The antibacterial mechanism of QPEI was also explored using enzyme activity measurement methods, in which the enzyme activity of two enzymes, beta-D-galactosidase and TTC-dehydrogenase, were measured. The experiments show that QPEI possesses outstanding antibacterial activity because of combination effect of the antibacterial groups on the macromolecular chains. The antibacterial ratio reached 100% for bacterium suspensions of 10(9) CFU/ml with a polymer concentration of 15 mg/l for a contact time of 4 min. The cationic degree influences the antibacterial ability of QPEI greatly, and the higher the cationic degree, the stronger the antibacterial activity. The experimental data indicated that the pI of the E. coli protein is probably 4.5. When pH > 4.5, the antibacterial activity of QPEI increases with increasing pH, and when pH > 6 the antibacterial ratio reaches a maximum and remain nearly constant. The enzyme activity measurement results reveal that the antibacterial action of QPEI is based on a sterilization process. Similar to the small molecular quaternary ammonium salt, QPEI causes cell death by disrupting cell membranes and releasing the intracellular contents.

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