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The dispersion copolymerization of n-butyl methacrylate (BMA) in methanol-water media has been investigated. The reactions were carried out in the presence of a series of poly(ethylene oxide) (PEO) macromonomers(1) (Ci-EO"-(CH2)m-S), with a p-alkylstyrene (S) end group, with m = 1,4, and 7 and = 53 and 110. Nearly monodisperse PBMA latex particles from 90 to 500 nm in diameter are obtained. Factors which affect the particle size are the structure and molecular weight of the macromonomers, initial BMA, initiator, and macromonomer concentrations, temperature, and the composition of the solvent. The particle radius (R) follows the relationship R = [ ] 0•82±0 06-[macromonomer]o_0 54±0 03n_0 30±0 02[initiator]o_010±0 01. The power law exponents are close to those predicted from a coagulative nucleation model, particularly the multibin kinetics model for coalescence among unstabilized particles developed by Paine [Macromolecules 1990, 23, 3109]. R is also found to decrease with an increase in temperature and also with an increase in m (in 1). R, however, also increases with an increasing volume fraction of water in the reaction medium. The mechanism for the dispersion copolymerization is discussed in detail.

Conformational properties of cylindrical rod brushes consisting of a flexible polystyrene main chain and poly(n-hexyl isocyanate) (PHIC) rod side chains have thoroughly been studied by static light and small-angle X-ray scattering (SAXS) in tetrahydrofuran (THF) at 25 °C. These rod brushes were prepared by radical homopolymerization of 4-vinylbenzyloxy-ended PHIC macromonomers (1) (VB-HIC-N s , where N s is the weight-averaged degree of polymerization of HIC and in a range from 21 to 80) in n-hexane at 60 °C. The mean-square cross-sectional radius of gyration (〈R c 2 〉 0 ) of the brush at an infinite dilution is determined by SAXS measurement and rationalized as a function of N s . The experimental value of 〈R c 2 〉 0 gradually increases with N s but above N s higher than 20 increases to follow the scaling law of 〈R c 2 〉 0 ∝ N s 0.87 . The experimental N s dependence of 〈R c 2 〉 0 is compared to that from the wormlike comb model whose main and side chains have different stiffness parameters. The molecular weight dependence of z-averaged mean-square radius of gyration (〈R g 2 〉 z ) of the brush is determined and analyzed in terms of the wormlike cylinder model taking into account the end effects. The parameters characteristic of the rod brush in THF solution, such as the main chain stiffness parameter (λ M -1 ), the molecular weight per unit contour length (M L ), and the excluded-volume strength (B), are determined and rationalized as a function of the contour length of the side rod. The polystyrene main chain stiffness of the rod brush remarkably increases by the densely located rod side chains to follow the scaling law of λ M -1 ∝ N s 1 . The backbone stiffness of the rod brush is higher than that of the flexible brush consisting of flexible polystyrene side chains with the corresponding contour length. A single rod brush of poly(VB-HIC-47) deposited on a mica surface is observed by the scanning force microscopy to reasonably demonstrate the cylindrical rod brushes.

The 2‐chloropropionamide derivative featuring an azido group is used as the initiator for the ATRP of N‐isopropylacrylamide (NIPAM) with copper(I) chloride (CuCl) and tris[2‐(dimethylamino)ethyl]amine (Me6TREN) to produce the PNIPAM end‐functionalized with an azido group. Subsequently, the ‘click’ reaction between the azido end‐group and acetylene derivatives is demonstrated to produce PNIPAM in which the end‐groups are modified by the phenyl, 4‐phenoxyphenyl, butyl, octyl, carboxylic acid, and hydroxymethyl groups. The resulting PNIPAM derivatives show a LCST that ranges from 34.8 to 44.6 °C depending on the introduced end‐group.magnified image

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