Cross-linked poly(4-vinylbenzyl chloride) (PVBC) microspheres were first synthesized by suspension copolymerization of 4-vinylbenzyl chloride (VBC) in the presence of a cross-linking agent, ethylene glycol dimethacrylate (EGDMA). Subsequent modification of the microsphere surfaces via surface-initiated atom transfer radical polymerization (ATRP) of 2-(dimethylamino)ethyl methacrylate (DMAEMA), using the VBC units of PVBC on the microsphere surface as the macroinitiators, gave rise to well-defined (nearly monodisperse) and covalently tethered poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) brushes. Quaternization of the tertiary amine groups of the PDMAEMA brushes with alkyl bromides (1-bromododecane or 1-bromohexane) gave rise to a high concentration of quaternary ammonium salt (QAS) on the microsphere surfaces. The chemical composition of the microsphere surfaces at various stages of surface modification was characterized by X-ray photoelectron spectroscopy (XPS). The bactericidal effect of the QAS-functionalized microspheres on Escherichia coli and Staphylococcus aureus was demonstrated. The permanence of the bactericidal activity was also demonstrated through the repeated applications of the surface-modified PVBC microspheres without any significant loss of their surface activity or functionality.

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The atom transfer radical bulk polymerization of styrene with FeX2 (X = Br or Cl)/tris(3,6‐dioxaheptyl) amine as the catalyst system was successfully implemented at 110 °C. The number‐average molecular weight of the polymers with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight = 1.2–1.5) increased linearly with the monomer conversion and matched the predicted molecular weight. The polymerization rate, initiation efficiency, and molecular weight distribution were influenced by the selection of the initiator and iron halide. The high functionality of the halide end group in the obtained polymers was confirmed by both 1H NMR and a chain‐extension reaction. Because of its water solubility, the iron complexes could be removed easily from the reaction mixture through the washing of the polymerization mixture with water. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 483–489, 2006

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Polycondensation and imidization of benzoguanamine and pyromellitic dianhydride under microwave radiation were studied. The effects of the microwave radiation time (power), the composition of the monomer on the imidization, and the polymer yield were discussed. The polycondensates' third-order optical nonlinearities and time responses were measured by a phase conjugate forward, 3-dimensional degenerate, four-wave mixing technique. At the same time they were compared with relevant conventional thermopolymerization. The results showed that the polycondensates had high third-order nonlinear optical coefficients [polyimide (PI) (3) ϭ 1.181 ϫ 10Ϫ13 esu] and fast time responses (22 ps). The third-order nonlinear optical coefficients under microwave radiation were higher than that of conventional thermopolymerization (microwave radiation PI (3) ϭ 1.181 ϫ 10 Ϫ13 esu: thermopolymerization PI (3) ϭ 0.686 ϫ 10 Ϫ13 esu). The experimental results also showed that the third-order optical nonlinearities were not only affected by the length of the polycondensate chain, but also the polycondensate -electron density distribution, which was explained and confirmed by computation with the semiempirical Austin method.