Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 52 Issue 14

15 July 2014

Volume 52, Issue 14

Pages i–iv, 1917–2081

  1. Cover Image

    1. Top of page
    2. Cover Image
    3. Articles
    1. You have free access to this content
      Cover Image, Volume 52, Issue 14 (pages i–ii)

      Version of Record online: 10 JUN 2014 | DOI: 10.1002/pola.27257

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      Three commercial bis-benzoxazine monomers based on the aniline derivatives of bisphenol A, bisphenol F, and 3,3′-thiodiphenol are examined using a variety of spectroscopic, chromatographic, and thermo-mechanical techniques. On page 2068 (DOI: 10.1002/pola.27231), Ian Hamerton, Lisa T. McNamara, Brendan J. Howlin, Paul A. Smith, Paul Cross, and Steven Ward report the polymerization kinetics are well described by an autocatalytic model. The kinetic data are compared with parallel studies involving chemically initiated benzoxazine monomers. Molecular simulation is used to examine the rotational freedom of the central bridging units, which is related to the degree of conversion achieved.

    2. You have free access to this content
      Cover Image, Volume 52, Issue 14 (pages iii–iv)

      Version of Record online: 10 JUN 2014 | DOI: 10.1002/pola.27258

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      Poly(ethylene glycol) end capped with biodegradable hydrophobic dipeptides shows versatile gelation behavior in a range of aqueous and organic solvents. On page 1917 (DOI: 10.1002/pola.27198), G. Rajesh Krishnan, Yuan Yuan, Ayesha Arzumand, and Debanjan Sarkar report this gelation characteristic is attributed to the aggregation of polymer chains induced by dipeptide end groups. These gels are biodegradable and possess physico-mechanical characteristics suitable for biomedical applications. Furthermore, proteins and hydrophobic model drugs can be encapsulated within the gels from aqueous and organic solvents, respectively, and can be released in a controlled fashion, indicating the potential application of the gels as drug delivery vehicles.

  2. Articles

    1. Top of page
    2. Cover Image
    3. Articles
    1. Gelation characteristics and applications of poly(ethylene glycol) end capped with hydrophobic biodegradable dipeptides (pages 1917–1928)

      G. Rajesh Krishnan, Yuan Yuan, Ayesha Arzumand and Debanjan Sarkar

      Version of Record online: 21 APR 2014 | DOI: 10.1002/pola.27198

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      Aggregation of poly(ethylene glycol) (PEG) end capped with tyrosine-derived dipeptides in various solvents leads to the formation of both hydrogel and organogels. Noncovalent interactions between the end groups associate end functionalized PEG to form physically cross-linked networks in presence of solvents. Morphologically, the gels contain interpenetrating nanosheet structures. The gels are biodegradable and posses physico-mechanical properties suitable for delivery of small molecules and proteins.

    2. Spotlight Article

      Effects of donor unit and π-bridge on photovoltaic properties of D–A copolymers based on benzo[1,2-b:4,5-c']-dithiophene-4,8-dione acceptor unit (pages 1929–1940)

      Haijun Bin, Lu Xiao, Yong Liu, Ping Shen and Yongfang Li

      Version of Record online: 28 APR 2014 | DOI: 10.1002/pola.27209

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      Four D-π-A type conjugated copolymers—PBDT-AT, PDTS-AT, PBDT-TT, and PDTS-TT—were designed and synthesized to investigate different donor and π-bridge effects on the optical and electrochemical properties, hole mobilities, and photovoltaic performance of the copolymers. The polymer solar cells based on PBDT-AT:PC70BM with methanol treatment showed a power conversion efficiency of 5.91%, under the illumination of AM 1.5 G 100 mW cm−2.

    3. Efficient one-pot synthesis of water-compatible and photoresponsive molecularly imprinted polymer nanoparticles by facile RAFT precipitation polymerization (pages 1941–1952)

      Yue Ma, Haiyang Li, Shangjin He, Hongtao Zhang and Huiqi Zhang

      Version of Record online: 30 APR 2014 | DOI: 10.1002/pola.27213

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      A facile, general, and highly efficient one-pot approach to obtain hydrophilic azobenzene (azo)-containing molecularly imprinted polymer nanoparticles with photoresponsive template binding and release properties in aqueous media is described. This involves the combined use of hydrophilic macromolecular chain transfer agentmediated reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization and easily available water-insoluble azo functional monomers.

    4. Healable dual organic–inorganic crosslinked sol–gel based polymers: Crosslinking density and tetrasulfide content effect (pages 1953–1961)

      Mina AbdolahZadeh, A. Catarina C. Esteves, Sybrand van der Zwaag and Santiago J. Garcia

      Version of Record online: 25 APR 2014 | DOI: 10.1002/pola.27200

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      Novel organic–inorganic sol–gel based polymers restore their integrity by selective breaking of tetrasulfide groups upon moderate thermo-mechanical stimulus. The hybrid sol–gel architecture offers an attractive combination of a tuneable mesoscopic flow due to the presence of thermo-responsive reversible bonds while preserving relatively high mechanical properties during the healing stage as a result of the stable crosslinked network.

    5. Self-immolative nanoparticles triggered by hydrogen peroxide and pH (pages 1962–1969)

      Zhijian Wang, Jianbo Sun and Xinru Jia

      Version of Record online: 22 APR 2014 | DOI: 10.1002/pola.27203

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      The azomethine-based oligomers bearing boronate groups and imine moieties in the main chain were synthesized from a dialdehyde monomer and p-phenylenediamine or ethylene diamine, respectively. Based on the oligomers, the nanoparticles with hydrogen peroxide (H2O2) and pH dual-responsive properties were constructed and encapsulated nile red inside. The degradation behavior of nanoparticles and the release of nile red triggered by H2O2 and pH were explored.

    6. High-performance field-effect transistors based on furan-containing diketopyrrolopyrrole copolymer under a mild annealing temperature (pages 1970–1977)

      Huajie Chen, Yunlong Guo, Zupan Mao, Dong Gao and Gui Yu

      Version of Record online: 22 APR 2014 | DOI: 10.1002/pola.27204

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      Two highly π-extended copolymers were designed and synthesized by copolymerizing furan-flanked diketopyrrolopyrrole units with (E)-2-(2-(thiophen-2-yl)vinyl)thiophene moieties for solution-processed polymer field-effect transistors (FETs). A typical nodular morphology with the ultrasmall lamellar distances of 16.84–19.15 Å had been demonstrated for the polymer thin films, therefore facilitating high-performance charge transport. The highest hole mobility without thermal annealing treatment reached 1.05 cm2 V−1 s−1. For the PDVF-8 thin films annealed at 100 ° C, moreover, an improved hole mobility of 1.90 cm2 V−1 s−1 was achieved, among the highest values of the reported polymer-based FETs fabricated from a mild temperature.

    7. Intramolecular donor–acceptor copolymers containing side-chain-tethered perylenebis(dicarboximide) moieties for panchromatic solar cells (pages 1978–1988)

      Tzong-Liu Wang, Yao-Yuan Chuang, Yeong-Tarng Shieh, Chien-Hsin Yang, Chin-Hsiang Chen and Tsung-Han Ho

      Version of Record online: 25 APR 2014 | DOI: 10.1002/pola.27205

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      When increasing the molar ratio of the PDI unit, the Voc could be raised and the power conversion efficiency of the photovoltaic devices have shown a significant improvement. On the whole, the device based on the P13:PC61BM blend with a molar ratio of 1:3 displayed the best performance with the optimal power conversion efficiency of 1.66%, highest Voc of 0.573 V and Jsc of 6.82 mA/cm2 without annealing and any additives.

    8. Electrochromic enhancement of poly(3,4-ethylenedioxythiophene) films functionalized with hydroxymethyl and ethylene oxide (pages 1989–1999)

      Shimin Zhang, Jingkun Xu, Baoyang Lu, Leiqiang Qin, Long Zhang, Shijie Zhen and Daize Mo

      Version of Record online: 21 APR 2014 | DOI: 10.1002/pola.27206

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      The electrosynthesis of poly(hydroxymethylated-3,4-ethylenedioxylthiophene) and ethylene oxide functionalized poly(3,4-ethylenedioxythiophene) are reported. In comparison with PEDOT, these polymers exhibit excellent electrochromic performances, including higher optical contrast ratio (57%), higher coloration efficiency (338 cm2 C−1), lower switching potential, fast response time, good electrochemical, and optical stability. They have promising potential applications in electrochromic devices and optical displays.

    9. Disulfide-centered star-shaped polypeptide-PEO block copolymers for reduction-triggered drug release (pages 2000–2010)

      Xiao Chang, Lisha Liu, Yanfei Guan and Chang-Ming Dong

      Version of Record online: 22 APR 2014 | DOI: 10.1002/pola.27207

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      Disulfide-centered star-shaped polypeptide-based block copolymers Cy-PZlys-b-PEO were successfully synthesized by combining ROP and thiol-yne chemistry. Despite a liquid crystal phase transition behavior, the inner α-helical PZlys blocks greatly suppressed the crystallinity of the outer PEO blocks. Cy-PZlys-b-PEO self-assembled into nearly spherical micelles, and these micelles were progressively reduced to smaller micelles in 10 mM 1,4-dithiothreitol, exhibiting a reduction-sensitivity. The DOX-loaded micelles presented a reduction-triggered profile, enhancing them useful for intracellular GSH-triggered drug delivery systems.

    10. Spotlight Article

      Pyrrolidone-functional smart polymers via nitroxide-mediated polymerization (pages 2011–2024)

      Xeniya Savelyeva and Milan Marić

      Version of Record online: 30 APR 2014 | DOI: 10.1002/pola.27208

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      A viable route toward thermoresponsive, pyrrolidone-functional polymers via nitroxide-mediated polymerization is presented. Pyrrolidone-rich poly(N-(2-methacryloyloxyethyl)-pyrrolidone-stat-9-(4-vinylbenzyl)-9H-carbazole) (MAEPYR-stat-VBK) statistical and block copolymers with water-soluble poly(dimethylacrylamide) were synthesized and controlled relatively well by low amounts of VBK comonomer in the feed (1–5 mol %). UV–Vis and dynamic light scattering were used to evaluate thermoresponsive behavior in aqueous media. Cloud point temperatures (CPTs) were tuned by altering VBK composition, heating rate, and solution concentration.

    11. Reversible fixation and release of carbon dioxide with a binary system consisting of polyethylene glycol and polystyrene-bearing cyclic amidine pendant group (pages 2025–2031)

      Mina Sakuragi, Naoto Aoyagi, Yoshio Furusho and Takeshi Endo

      Version of Record online: 1 MAY 2014 | DOI: 10.1002/pola.27210

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      The polystyrene bearing cyclic amidine pendant groups was synthesized via free radical polymerization of the HCl salt of the corresponding styrene monomer followed by neutralization. For comparison, the polystyrene bearing N-formyl-1,3-propanediamine pendant groups was prepared through hydrolysis of the amidine polymer. It was found that the binary system of the amidine polymer and PEG captured and released CO2 more efficiently than that of the N-formyl-1,3-propanediamine polymer and PEG.

    12. Bis(4-nitrophenyl) phosphate as an efficient organocatalyst for ring-opening polymerization of β-butyrolactone leading to end-functionalized and diblock polyesters (pages 2032–2039)

      Kosuke Makiguchi, Tatsuya Saito, Toshifumi Satoh and Toyoji Kakuchi

      Version of Record online: 2 MAY 2014 | DOI: 10.1002/pola.27211

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      The bis(4-nitrophenyl) phosphate-catalyzed ring-opening polymerization of β-butyrolactone (β-BL) efficiently proceeded via monomer and initiator/chain-end activation, leading to well-defined poly(β-butyrolactone) (PBL) with controlled molecular weight and polydispersity. Functional initiators were applicable for synthesizing various end-functionalized PBLs. In addition, diblock copolymerization of ε-caprolactone or trimethylene carbonate with β-BL proceeded successfully in a one-pot synthesis.

    13. Spotlight Article

      Thiol-epoxy polymerization via an AB monomer: Synthetic access to high molecular weight poly(β-hydroxythio-ether)s (pages 2040–2046)

      Selmar Binder, Ikhlas Gadwal, Andreas Bielmann and Anzar Khan

      Version of Record online: 25 APR 2014 | DOI: 10.1002/pola.27212

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      An AB type of monomer carrying an epoxy and a thiol group is synthesized. Base-catalyzed thiol-epoxy polymerization of this monomer gave access to reactive and functionalizable poly(β-hydroxythio-ether)s. The molecular weight of the polymers resulting from the present AB monomer route was found to be five times higher than the molecular weight of the polymers prepared through a previously reported AA/BB approach.

    14. Suppressing charge recombination by incorporating 3,6-carbazole into poly[9-(heptadecan-9-yl)-9H-carbazole-2,7-diyl-alt-(5,6-bis-(octyloxy)-4,7-di(thiophen-2-yl)benzo[1,2,5]-thiadiazole)-5,5-diyl] (pages 2047–2056)

      Gang-Young Lee, Byung-Joon Moon, Seulki Song, Won Ho Lee, Han Young Woo and Taiho Park

      Version of Record online: 4 MAY 2014 | DOI: 10.1002/pola.27214

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      A series of copolymers were synthesized based on alkoxy-bis(bromothienyl)benzo-thiadiazole with various amounts of 3,6-carbazole. P0.02, which incorporated 2% of 3,6-carbazole, exhibited a good photovoltaic performance (3.8–5.3%). This improvement largely arose from suppressed nongeminated recombination owing to the strong intermolecular interactions of the 3,6-carbazole moieties. Appropriate quantities of the 3,6-carbozole units enhanced the hole mobility by introducing conjugation breaks that improved the intermolecular interactions; however, an excess appeared to hamper hole transport, thereby increasing recombination reactions in the polymer solar cells.

    15. Tuning amphiphilicity/temperature-induced self-assembly and in-situ disulfide crosslinking of reduction-responsive block copolymers (pages 2057–2067)

      Nicky Chan, Nathan Yee, So Young An and Jung Kwon Oh

      Version of Record online: 28 APR 2014 | DOI: 10.1002/pola.27216

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      Reductive- and thermo-responsive poly(ethylene oxide)-based block copolymers with tunable amphiphilicity/temperature induced self-assembly were synthesized by ARGET ATRP. By varying the ratio of hydrophilic to pendant disulfide containing monomers, the amphiphilicity and in-situ disulfide crosslinking of reduction-responsive copolymers could be tuned to yield self-assembled nanogels via temperature induced self-assembly exhibiting enhanced colloidal stability upon dilution.

    16. Examining the kinetics of the thermal polymerization of commercial aromatic bis-benzoxazines (pages 2068–2081)

      Ian Hamerton, Lisa T. McNamara, Brendan J. Howlin, Paul A. Smith, Paul Cross and Steven Ward

      Version of Record online: 14 MAY 2014 | DOI: 10.1002/pola.27231

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      Three bis-benzoxazine monomers based on the aniline derivatives of bisphenol A (BA-a), bisphenol F (BF-a), and 3,3′-thiodiphenol (BT-a) are examined using a variety of spectroscopic, chromatographic and thermo-mechanical techniques. The kinetics of the polymerization of BA-a were found to be well described using an autocatalytic model.