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Volume 42 Issue 8, August 2010

Half generation poly(amidoamine) (G0.5 PAMAM) dendrimer

See the article by Yuka Tanaka and Kensuke Naka, A carbonate controlled-addition method for size-controlled calcium carbonate spheres by carboxylic acid terminated poly(amidoamine) dendrimers on page 676.

Invited Review

  • The slow mode in semidilute neutral polymer solutions, dilute polyelectrolyte solutions and gels, is reviewed here. Our results suggest that the slow mode can be qualitatively considered as a hindered motion of interacting chains, even though the nature of interaction can be very different; namely, from the weak segment-segment interaction in a less good solvent to a strong electrostatic interaction among polyelectrolyte chains, and even to chemical crosslinking inside gel networks.

    • Junfang Li
    • To Ngai
    • Chi Wu
    Invited Review

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Invited Article

  • 1-Adamantyl methacrylate (AdMA) was polymerized using atom transfer radical polymerization (ATRP), producing the well-defined poly(1-adamantyl methacrylate) (PAdMA). Simultaneous control of the molecular weight and tacticity of PAdMA was achieved by ATRP in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Block copolymerization of AdMA and methyl methacrylate (MMA) was achieved by activators generated by electron transfer (AGET) ATRP method. Differential scanning calorimetry (DSC) measurement revealed the relationship among the glass transition temperature, molecular weight and tacticity of PAdMA.

    • Keita Fuchise
    • Masako Sone
    • Toyoji Kakuchi
    Invited Article
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Original Article

  • Asymmetric anionic homopolymerizations of N-4′-benzo 15-crown-5 maleimide (B15C5MI) were carried out with a chiral anionic initiator consisting of organometal and chiral ligand to obtain optically active polymers. Chiroptical properties and structures of the polymers obtained were analyzed by CD, UV, NMR and gel permeation chromatography measurements. The additional effects of (R)-cyclohexylethylamine ((R)-Cyc) to the obtained poly(B15C5MI) were investigated.

    • Motohisa Azechi
    • Kazuhiro Yamabuki
    • Tsutomu Oishi
    Original Article
  • Aniline sulfide resin (ASR) is synthesized by the reaction of aniline and sulfide dichloride. Crosslinked ASR (ASC) has been prepared in the presence of ammonium peroxydisulfate and aniline in aqueous solution as oxidant and monomer, respectively. By changing the ratio of ASR to aniline during the polymerization reaction, it is possible to control the number of crosslinked sites, electrical conductivity, molecular weight and solubility. Electropolymerization was carried out by coating ASR on the surface of glassy carbon disk electrode, and then grown on a graft copolymer ASC in the presence of fresh aniline and acidic solution. Electrical conductivity of ASC has been studied by four-point probe method and produced 8.5 × 10−3 S cm–1 conductivity for it.

    • Seyed Hossein Hosseini
    • Maryam Malekdar
    • Shaghayegh Naghdi
    Original Article
  • Novel fluorescent polyimides (PIs) were prepared from a new diamine, 4-(4-(4-amino-2-(4,5-diphenyl-1Hi-midazol-2-yl)phenoxy)phenoxy)-3-(4,5-diphenyl-1H-imidazol-2-yl)benzenamine(DA), and three tetracarboxylic dianhydrides. The PIs are amorphous and soluble in polar aprotic solvents and demonstrate a film-forming capability; their inherent viscosities ranged from 43 to 82 ml g−1. The PIs show emission in dilute (0.2 g per 100 ml) N,N-dimethyl acetamide solution with photoluminescence (PL) quantum yields in the range of 11–25%. The chemiluminescence (CL) activity of PIs in the presence of peroxyoxalate was also investigated.

    • Mousa Ghaemy
    • Seyed Mojtaba Amini Nasab
    Original Article
  • Optical properties of thin films based on thermostable poly(oxadiazole-naphthylimide)s were investigated. The main absorption maxima of the films were centered at about 301–308 nm, their intensity and positions remaining almost unchanged up to 250 °C. The Kramers–Kronig analysis applied to the reflectance spectra yielded the extinction coefficient and refractive index values. The energy gaps obtained from the edge of the absorption coefficient, based on transmission and reflectivity measurements, were found in the range of 2.77–3.04 eV. In photoluminescence spectra, three maxima in the UV and blue spectral range were detected.

    • Mariana-Dana Damaceanu
    • Radu-Dan Rusu
    • Bozena Jarzabek
    Original Article
  • When poly(methyl methacrylate) (PMMA) film doped with (Z)-N-acetyl-α-dehydroarylalanine naphthyl esters ((Z)-1) was irradiated with unfiltered light from a high-pressure mercury lamp, (Z)-1 underwent heterolytic cleavage of the ester bond preferentially in PMMA film to give arylmethylene-substituted oxazolone and naphthol derivatives as major products. This photochemical transformation enhanced the refractive index of this polymer film in the range of 0.001–0.020, depending on the structure of the aryl substituents.

    • Haruki Nakajima
    • Hiroshi Komatsu
    • Tadamitsu Sakurai
    Original Article
  • Vaterite particles were obtained by a ‘carbonate controlled-addition method’ by G0.5 poly(amidoamine) (PAMAM) dendrimer with carboxylate groups at the external surface. The average particle sizes of the spheres decreased from 2.2±0.2 to 0.61±0.24 μm and the stability of the spheres increased with an increase in the incubation time of the G0.5–CaCl2 solution from 3 min to 24 h. The interaction and reaction kinetics of the dendrimer–Ca2+ complex have an important role in the mineralization of CaCO3.

    • Yuka Tanaka
    • Kensuke Naka
    Original Article
  • Sulfonated free-standing films were prepared by sulfonation of the free-standing films of 3-mercaptopropyl(trimethoxy)silane (MTMS)/1,2-bis(triethoxysilyl)ethane (BTESE) copolymers. The sulfonyl group content was 1.23 mmol g−1 when the composition of MTMS/BTESE was 1:2, which sulfonyl group content at 150 °C was 1.20 mmol g−1.

    • Takahiro Gunji
    • Yasunobu Shigematsu
    • Yoshimoto Abe
    Original Article
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