Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Journal of Polymer Science Part A: Polymer Chemistry

15 March 2003

Volume 41, Issue 6

Pages 725–871

  1. Rapid Communication

    1. Top of page
    2. Rapid Communication
    3. Articles
    1. Novel light-emitting polymers containing donor and acceptor architectures (pages 725–731)

      Yun Chen, Rong-Bin Sheu and Tzi-Yi Wu

      Article first published online: 23 JAN 2003 | DOI: 10.1002/pola.10621

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      We present the synthesis and properties of four novel donor–acceptor conjugated polymers composed of iminodibenzyl, distyrylbenzene, and 1,3,4-oxidazole units. The absorption and photoluminescence spectra are mainly determined by the donor segments (iminodibenzyl and distyrylbenzene) or conjugation length (1,3,4-oxidazole and pendant 1,3,4-oxidazole) of the acceptor segments. Electrochemical studies reveal that P1P4 possess high-lying highest occupied molecular orbital energy levels (from −5.14 to −5.24 eV) and low-lying lowest unoccupied molecular orbital energy levels (from −2.63 to −2.83 eV) because of the alternate donor and acceptor conjugated units. The brightness and luminence efficiency of ITO/P2/Al configuration were up to 1864 cd/m2 and 0.22 cd/A, respectively.

  2. Articles

    1. Top of page
    2. Rapid Communication
    3. Articles
    1. Cationic polymerization of norbornadiene (pages 732–739)

      Ralf M. Peetz, Ahmed F. Moustafa and Joseph P. Kennedy

      Article first published online: 24 JAN 2003 | DOI: 10.1002/pola.10611

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      The controlled polymerization of norbornadiene initiated by the 2-chloro-2,4,4-trimethylpentane/titanium tetrachloride system was investigated. The microstructure (i.e., head and tail groups and endo/exo enchainment) of the polynorbornadiene (PNBD) produced was elucidated by high-resolution 1H and 13C NMR spectroscopy. The plot of the glass-transition temperature against the reciprocal of the number-average molecular weight was linear and yielded a glass-transition temperature of 323 °C for the infinite molecular weight polymer.

    2. Synthesis and characterization of two novel star blocks: tCum[poly(isobutylene-b-norbornadiene)]3 and tCum[poly(norbornadiene-b-isobutylene)]3 (pages 740–751)

      Ralf M. Peetz, Ahmed F. Moustafa and Joseph P. Kennedy

      Article first published online: 29 JAN 2003 | DOI: 10.1002/pola.10610

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      Two structurally closely related three-arm star blocks were synthesized and characterized: tCum(PIB-b-PNBD)3 and tCum(PNBD-b-PIB)3 [where tCum (tricumyl) stands for the phenyl-1,3,5-tris(-2-propyl) fragment and PIB and PNBD are polyisobutylene and polynorbornadiene, respectively]. The syntheses were accomplished in two stages: (1) the preparation of the first (or inner) block fitted with appropriate chlorine termini capable of initiating the polymerization of the second (or outer) block with TiCl4 and (2) the mediation of the polymerization of the second block. The overall number-average molecular weights (Mn's) of tCum(PIB-b-PNBD)3 were 107,300–109,200 g/mol, and the dispersity was remarkably low (weight-average molecular weight/number-average molecular weight ∼ 1.01). The Mn of tCum(PNBD-b-PIB)3 was 14,200 g/mol. NMR spectroscopy (750 MHz) was used to determine structures and molecular weights. Both star blocks showed two glass-transition temperatures, one each for the PIB and PNBD phases. It is of special interest that the sec-chlorine (Clsec) of the chemical structure image terminus in tCum(PNBD-Clsec)3 readily initiated isobutylene polymerization.

    3. Catalytic-chain-transfer polymerization of styrene revisited: The importance of monomer purification and polymerization conditions (pages 752–765)

      G. Evan Roberts, Johan P. A. Heuts and Thomas P. Davis

      Article first published online: 23 JAN 2003 | DOI: 10.1002/pola.10613

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      The cobaloxime-mediated catalytic-chain-transfer polymerization of styrene at 60 °C was studied with an emphasis on the effects of monomer purification and polymerization conditions. Commonly used purification procedures were not sufficient to obtain adequate kinetic information, and a very rigorous method was required. Careful kinetic experiments confirmed that the measured chain-transfer constant decreased with increasing initiator concentration and conversion and that the presence of light increased the amount of free Co(II) catalyst in agreement with other studies.

    4. Fluorescent polymer particles by emulsion and miniemulsion polymerization (pages 766–778)

      Frédéric Tronc, Mei Li, Jianping Lu, Mitchell A. Winnik, Bansi Lal Kaul and Jean-Christophe Graciet

      Article first published online: 27 JAN 2003 | DOI: 10.1002/pola.10619

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      This article describes the synthesis and characterization of latex particles labeled with a brightly fluorescent yellow dye (HY) based on the benzothioxanthene ring structure. Three dye derivatives were synthesized with different spacers connecting the HY nucleus to a methacrylate group. Reactivity ratios with styrene and with butyl methacrylate were determined, and these predict random dye incorporation if the amount of dye in the feed is small. Seeded emulsion polymerization fails to lead to significant dye incorporation unless large amounts of non-ionic surfactant were present. In contrast, miniemulsion polymerization worked well to yield latex particles of polystyrene, poly(butyl methacrylate) and poly(methyl methacrylate) with essentially quantitative dye incorporation.

    5. Newly designed hydrogel with both sensitive thermoresponse and biodegradability (pages 779–787)

      Takatsune Yoshida, Takao Aoyagi, Etsuo Kokufuta and Teruo Okano

      Article first published online: 23 JAN 2003 | DOI: 10.1002/pola.10595

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      The synthesis and characterization of a hydrogel based on N-isopropylacrylamide (IPAAm) crosslinked with biodegradable poly(amino acid) is described. The hydrogel showed a good thermoresponse and temperature-modulated biodegradation, therefore, it could be applied to an injectable matrix for drug controlled release.

    6. Batch emulsion copolymerization of 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose and butyl acrylate: Synthesis and properties of the sugar latices (pages 788–803)

      U. Koch and E.-J. Yaacoub

      Article first published online: 29 JAN 2003 | DOI: 10.1002/pola.10625

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      New latices based on sugar derivative (3-MDG) and n-butyl acrylate (BA) were synthesized in batch emulsion polymerization. 3-MDG polymerizes faster than BA and leads to a polymer composition drift. The overall rate of polymerization increases and kp decreases by enhancing the sugar content in the initial monomer composition. The sugar latices exhibit a shear thinning or shear thickening on the pH of the latex and on the AA concentration on the particles surface.

    7. Sterically stabilized emulsion polymerization of styrene: Pseudo-semicontinuous approach (pages 804–820)

      I. Capek, J. Chudej and S. Janíčková

      Article first published online: 30 JAN 2003 | DOI: 10.1002/pola.10627

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      The sterically stabilized emulsion polymerization of styrene initiated by a water-soluble initiator at different temperatures has been investigated. The rate of polymerization (Rp) versus conversion curve shows the two non-stationary-rate intervals typical for the polymerization proceeding under the non-stationary-state conditions. The average size of monomer/polymer particles strongly decreased up to about 40% conversion and then leveled off. The initial large particles are assumed to be highly monomer-swollen particles formed by the heteroagglomeration of unstable polymer particles and monomer droplets. The size of the “highly monomer” swollen particles continuously decreases with conversion, and they merge with the growing particles at about 40–50% conversion. The monomer droplets and/or large highly monomer-swollen polymer particles also serve as a reservoir of monomer and emulsifier.

    8. Solution polycondensation of isophthalic acid/terephthalic acid and tetrachlorobisphenol A of low polymerizability with tosyl chloride/dimethylformamide/pyridine improved by the introduction of comonomers of smaller sizes (pages 821–830)

      Fukuji Higashi and Miwako Moriya

      Article first published online: 30 JAN 2003 | DOI: 10.1002/pola.10639

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      Polyesterification with tetrachlorobisphenol A (TC-BPA) of low polymerizability was greatly improved by the incorporation of dihydroxybenzenes of a smaller size, yielding copolymers of high molecular weights. This was examined with distributions of the TC-BPA unit segments in the resulting copolymers determined by NMR in terms of the deviation and depression of the intermolecular associations of the segments.

    9. Real-time Fourier transform infrared study of the free-radical ultraviolet-induced polymerization of a hybrid sol–gel. II. The effect of physicochemical parameters on the photopolymerization kinetics (pages 831–840)

      O. Soppera and C. Croutxé-Barghorn

      Article first published online: 31 JAN 2003 | DOI: 10.1002/pola.10623

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      Real-time Fourier transform infrared spectroscopy was used to study the photopolymerization of a hybrid sol–gel under ultraviolet irradiation. Various photoinitiator systems were tested for their efficiency in inducing the polymerization of pendant polymerizable moieties anchored on a partially condensed silicate network. The presence of O2 and the nature of the polymerizable function were demonstrated to be crucial factors in the photoinduced process. The effects of the photoinitiator concentration and light intensity were also studied.

    10. Novel functional polymers: Poly(dimethyl siloxane)–polyamide multiblock copolymers. XI. The effects of sequence regularity on the thermal and mechanical properties (pages 841–852)

      Eui-Chul Kang, Tatsuo Kaneko, Daijiro Shiino and Mitsuru Akashi

      Article first published online: 31 JAN 2003 | DOI: 10.1002/pola.10640

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      Alternately sequenced poly(aramid silicone) (PAS) multiblock copolymers behaved like a very soft rubber, showing a high value of elongation at the breaking point, unlike randomly sequenced PAS.

    11. Samarium enolate on crosslinked polystyrene beads. II. An anionic initiator for the well-defined synthesis of poly(allyl methacrylate) on a solid support (pages 853–860)

      Masayoshi Tanaka, Atsushi Sudo, Fumio Sanda and Takeshi Endo

      Article first published online: 31 JAN 2003 | DOI: 10.1002/pola.10626

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      A resin-supported samarium enolate successfully initiated the polymerization of allyl methacrylate and methyl methacrylate in a living anionic fashion to afford the corresponding homopolymer and the respective block copolymer with well-controlled molecular weights. These could be quantitatively isolated from the resin by a trifluoroacetic acid treatment.

    12. Photosensitive fluorinated polyimides with a low dielectric constant based on reaction development patterning (pages 861–871)

      Tomoko Miyagawa, Takafumi Fukushima, Toshiyuki Oyama, Takao Iijima and Masao Tomoi

      Article first published online: 31 JAN 2003 | DOI: 10.1002/pola.10638

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      A photosensitive polyimide, consisting of a nonsensitive fluorinated polyimide PI(6FDA/HFBAPP), where 6FDA is 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and HFBAPP is 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane with a low dielectric constant of 2.41 at 20 GHz and diazonaphthoquinone (DNQ) as a photosensitive agent, exhibited good positive photosensitivity and resolution (line/space = 10/10 μm) according to reaction development patterning for which a reactive developer including ethanolamine was employed. A PI(6FDA/HFBAPP)/DNQ film also showed a low dielectric constant of 2.63 at 20 GHz.

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