Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 44 Issue 4

15 February 2006

Volume 44, Issue 4

Pages 1347–1567

  1. Articles

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Note
    1. Gradient graft copolymers derived from PEO-based macromonomers (pages 1347–1356)

      Dorota Neugebauer, Ying Zhang and Tadeusz Pakula

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21244

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      The atom transfer radical polymerization (ATRP) of high and low MW PEO macromonomers was performed in organic solvent via the grafting through method. The selection of PEO methacrylate with methyl group (PEOMeMA, DPPEO = 23) vs PEO acrylate end-capped by phenyl ring (PEOPhA, DPPEO = 4) led to the formation of copolymers with a spontaneous gradient in PEO graft compositions. It was caused due to different reactivity ratios of comonomers. The mechanical measurements of copolymers consisting of amorphous PEOPhA units and crystallizable PEOMeMA segments indicated elastomeric properties in the range of soft rubber (G′ ∼ 104 Pa, G′ ≫ G″).

    2. Syntheses and self-assembly of poly(benzyl ether)-b-poly(N-isopropylacrylamide) dendritic–linear diblock copolymers (pages 1357–1371)

      Zhishen Ge, Shizhong Luo and Shiyong Liu

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21261

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      Poly(benzyl ether)-b-poly(N-isopropylacrylamide) dendritic–linear diblock copolymers have been prepared by the reversible addition–fragmentation transfer polymerization of N-isopropylacrylamide with reversible addition–fragmentation transfer agents based on poly(benzyl ether) monodendrons of the second or third generation. The thermoresponsive conformational changes of poly(N-isopropylacrylamide) chains located at the shell of the dendritic–linear diblock copolymer micelles have been thoroughly investigated with a combination of dynamic and static laser light scattering and excimer fluorescence measurements.

    3. Novel route to dendritic structures and their application for surface modification (pages 1372–1386)

      Sandra Reemers, Ahmed Mourran, Helmut Keul and Martin Möller

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21251

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      This study demonstrates a simple synthetic strategy for forming dendritic urethanes containing long alkyl chains. The dendritic polyurethanes demonstrate a remarkable potential to form ordered layers. The functional groups within the chain branches ensure adequate interactions between the arms and with a polar substrate via hydrogen bonds. Surfaces coated with these materials are hydrophobic.

    4. Spherically propagating thermal polymerization fronts (pages 1387–1395)

      Burcu Binici, Dionne I. Fortenberry, Kayce C. Leard, Marcus Molden, Nesrin Olten, Sam Popwell and John A. Pojman

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21246

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      A front of polymerization is propagating from a site of photochemical initiation. The system consists of a gel created by the amine-catalyzed thiol addition of a trithiol to a triacrylate in a 1:4 ratio. The remaining triacrylate supports thermal frontal polymerization via a peroxide initiator.

    5. Photoresponsive poly(methyl methacrylate)2–(polystyrene)2 miktoarm star copolymer containing an azobenzene moiety at the core (pages 1396–1403)

      Tuba Erdogan, Eda Gungor, Hakan Durmaz, Gurkan Hizal and Umit Tunca

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21253

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      The mikto-functional initiator, 3, with tertiary bromide (for ATRP) and 2,2,6,6-tetramethylpiperidin-1-yloxy (TEMPO) (for NMP) functionalities and an azobenzene moiety at the core was synthesized. The initiator 3 thus obtained was employed in consecutive living radical polymerization routes such as ATRP of MMA and NMP of St, respectively, to give A2B2 type miktoarm star copolymer, (PMMA)2-(PSt)2 with an azobenzene unit at core with controlled molecular weight and low polydispersity (Mw/Mn < 1.15). The photoresponsive properties of 3 and (PMMA)2-(PSt)2 miktoarm star copolymer were investigated.

    6. Integrated surface modification of fully polymeric microfluidic devices using living radical photopolymerization chemistry (pages 1404–1413)

      Robert P. Sebra, Kristi S. Anseth and Christopher N. Bowman

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21247

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      Presented is a microfluidic device illustrating directed H2O flow via spatially photografted channels modified with hydrophilic poly(ethylene glycol) (375) monoacrylate and hydrophobic trifluoroethyl acrylate (TFEA). As shown by the dyed blue water, the fluid flow only follows the channels in regions modified with the poly(ethylene glycol) (375) monoacrylate monomer. The hydrophobic, TFEA-modified regions prevent fluid flow.

    7. Synthesis, characterization, and properties of new sequenced poly(ether amide)s based on 2-(4-aminophenyl)-5-aminobenzimidazole and 2-(3-aminophenyl)-5-aminobenzimidazole (pages 1414–1423)

      Vanesa Ayala, Dulce M. Muñoz, Ángel E. Lozano, José G. de la Campa and Javier de Abajo

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21260

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      New poly(ether amide)s were prepared from two benzimidazole diamines, 2-(4-aminophenyl)-5-aminobenzimidazole and 2-(3-aminophenyl)-5-aminobenzimidazole, and various oligo(ethylene oxide)dibenzoyl chlorides via the general method of solution polycondensation at low temperatures. The polymers were attained in high yields and with high molecular weights, and they all were soluble in polar aprotic solvents. The number of ether linkages of the repeat units played an important role in the properties, such as the glass-transition temperature, mechanical resistance, and water uptake. The phenylene ring orientation, meta or para, of the diamine moiety also influenced the glass-transition temperatures of the poly(ether amide)s.

    8. Preparation, characterization, and polymerization of maleimidobenzoxazine monomers as a novel class of thermosetting resins (pages 1424–1435)

      Tarek Agag and Tsutomu Takeichi

      Article first published online: 3 JAN 2006 | DOI: 10.1002/pola.21245

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      New series of benzoxazine-based monomers, namely maleimidobenzoxazines, were prepared with hydroxyphenylmaleimide, formalin, and various amines, such as aniline, allylamine, and aminophenyl propargyl ether. The thermal cure of the monomers at 250 °C afforded a novel network structure. The dynamic mechanical analyses of the thermosets derived from maleimidobenzoxazine showed that the glass-transition temperatures were as high as 241–335 °C and that the storage moduli were kept constant up to high temperatures. The thermosets did not show any weight loss up to about 350 °C, with char yields ranging from 62 to 70% at 800 °C.

    9. Synthesis of well-defined syndiotactic poly(methyl methacrylate) with low-temperature atom transfer radical polymerization in fluoroalcohol (pages 1436–1446)

      Yutaka Miura, Toshifumi Satoh, Atsushi Narumi, Osamu Nishizawa, Yoshio Okamoto and Toyoji Kakuchi

      Article first published online: 6 JAN 2006 | DOI: 10.1002/pola.21249

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      The atom transfer radical polymerization of methyl methacrylate (MMA) in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was studied to simultaneously control the molecular weight and tacticity. The polymerization using tris[2-(dimethylamino)ethyl]amine (Me6TREN) as a ligand was performed even at −78 °C with a number-average molecular weight (Mn) of 13,400, a polydispersity (Mw/Mn) of 1.31, and a rr content of 84%. The addition of copper(II) bromide (CuBr2) apparently affected the early stage of the polymerization, that is, the polymerization could proceed in a controlled manner at −20 °C with the MMA/HFIP (ν/ν) of 1/4.

    10. Reactivity of silicon-based epoxy monomers as studied by near-infrared spectroscopy and multivariate curve resolution methods (pages 1447–1456)

      L. A. Mercado, M. Galià, J. A. Reina, M. Garrido, M. S. Larrechi and F. X. Rius

      Article first published online: 9 JAN 2006 | DOI: 10.1002/pola.21254

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      As a model system of silicon-based epoxy monomers, the reaction of glycidyloxydimethylphenyl silane with aniline was monitored in situ with near-infrared spectroscopy, and with multivariate curve resolution/alternating least squares, the evolution of the concentration of each species throughout the reaction was obtained. The results showed that the reactivity of the silicon-based epoxy monomer was higher and that its ring opening reaction was faster because of electronic effects.

    11. Synthesis of poly[N-isopropylacrylamide-g-poly(ethylene glycol)] with a reactive group at the poly(ethylene glycol) end and its thermosensitive self-assembling character (pages 1457–1469)

      Michihiro Iijima and Yukio Nagasaki

      Article first published online: 9 JAN 2006 | DOI: 10.1002/pola.21264

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      Poly[N-isopropylacrylamide-g-poly(ethylene glycol)]s with a reactive group at the poly(ethylene glycol) (PEG) end were synthesized by the radical copolymerization of N-isopropylacrylamide with a PEG macromonomer having an acetal group at one end and a methacryloyl group at the other chain end via an aqueous redox polymerization. The obtained graft copolymers were soluble in aqueous media at low temperatures, whereas self-assembled nanoparticles were observed above 40°C; totally transparent solutions were retained. The acetal groups on the nanoparticle surface were converted to the aldehyde groups, which could be used as ligand-installation sites.

    12. Synthesis and characterization of fluorinated telomers containing vinylidene fluoride and hexafluoropropene from 1,6-diiodoperfluorohexane (pages 1470–1485)

      G. Mladenov, B. Ameduri, G. Kostov and R. Mateva

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21263

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      The telomerization of vinylidene fluoride (VDF) and the cotelomerization of VDF and hexafluoropropene were carried out as shown. Molecular weights ranging from 1200 to 12,700 g/mol (assessed by NMR) were obtained, and their thermal properties were investigated.

    13. Reactivity of styrene and substituted styrenes in the presence of a homogeneous isospecific titanium catalyst (pages 1486–1491)

      Francesco De Carlo, Carmine Capacchione, Vincenzo Schiavo and Antonio Proto

      Article first published online: 11 JAN 2006 | DOI: 10.1002/pola.21267

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      The isospecific polymerization of several para-substituted styrenes was performed in the presence of the catalyst dichloro[1,4-dithiabutanediyl-2,2′-bis(4,6-di-tert-butyl-phenoxy)] titanium activated by methylaluminoxane. The presence of electron-donating substituents on the aromatic ring had a positive effect on the catalyst activity, whereas the electron-withdrawing substituents affected the polymerization activity negatively. Binary copolymerizations of the various substituted styrenes showed an inversion of the reactivity with respect to that observed in the homopolymerization. These results suggested that the last monomer unit of the polymer chain coordinated to the metal center, influencing the reactivity of the catalyst with respect to the incoming monomer.

    14. Effects of end group polarity and molecular weight on the lower critical solution temperature of poly(N-isopropylacrylamide) (pages 1492–1501)

      Steven Furyk, Yanjie Zhang, Denisse Ortiz-Acosta, Paul S. Cremer and David E. Bergbreiter

      Article first published online: 11 JAN 2006 | DOI: 10.1002/pola.21256

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      The effect of molecular weight, polydispersity, and end-group polarity on the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM) was studied. Polydispersity or end-group structure has no effect on LCSTs, if the Mw is above 100 kDa. At lower molecular weights, end group polarity affected the LCST, with polar groups increasing the LCST and nonpolar groups lowering the LCST.

    15. Preparation and characterization of optically active polymers containing pendent and terminal chiral units via atom transfer radical polymerization (pages 1502–1513)

      Wenjian Xu, Xiulin Zhu, Jian Zhu and Zhenping Cheng

      Article first published online: 11 JAN 2006 | DOI: 10.1002/pola.21284

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      Well-defined optically active polymers with pendent chiral units were obtained via the atom transfer radical polymerization (ATRP) of pregnenolone methacrylate, β-cholestanol acrylate, and 20-(hydroxymethyl)-pregna-1,4-dien-3-one acrylate with ethyl 2-bromopropionate as the initiator and CuBr/N,N,N′,N″,N″-pentamethyldiethylenetriamine as the catalytic system. In addition, when the optically active initiators estrone 2-bromopropionate and 20-(hydroxymethyl)-pregna-1,4-dien-3-one 2-bromopropionate were used for ATRPs of methyl methacrylate and styrene, terminal optically active poly(methyl methacrylate) and polystyrene were obtained.

    16. Vinyl polymerization of norbornene by bis(nitro-substituted-salicylaldiminate)nickel(II)/methylaluminoxane catalysts (pages 1514–1521)

      Carlo Carlini, Marco Martinelli, Anna Maria Raspolli Galletti and Glauco Sbrana

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21279

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      The polymerization of norbornene (NB) in the presence of different bis(salicylaldiminate)nickel(II) complexes and methylaluminoxane was investigated. In all cases, a high-molecular-weight vinyl-type polymer was obtained. The presence of electron-withdrawing nitro groups on the chelate ligand markedly increased the activity of the catalyst. The influence on the catalytic performances and polymer characteristics as a function of the reaction parameters, such as the solvent, NB/Ni and Al/Ni molar ratios, temperature, and duration, was studied.

    17. Preparation and characterization of optically active polystyrene via a chiral nitroxide-mediated polymerization (pages 1522–1528)

      Nianchen Zhou, Wenjian Xu, Yu Zhang, Jian Zhu and Xiulin Zhu

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21250

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      2,2,6,6-Tetramethyl-4-[d-(+)-10-camphorsulfonyl]-1-piperidinyloxy was synthesized and used as a chiral nitroxide for bulk polymerizations of styrene initiated with benzoyl peroxide, tetraethylthiuram disulfide, and thermal initiation. The results showed that the polymerizations proceeded in a controlled/living way, successful chain-extension reactions were carried out, and the structures of the obtained polymers were characterized by gel permeation chromatography and 1H NMR. The specific rotations of the polymers were also measured by polarimetric analysis.

    18. Synthesis of novel benzoxazines containing glycidyl groups: A study of the crosslinking behavior (pages 1529–1540)

      R. Andreu, M. A. Espinosa, M. Galià, V. Cádiz, J. C. Ronda and J. A. Reina

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21255

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      Benzoxazines derived from aniline and 4-hydroxybenzoic acid and from phenol and 4-aminobenzoic acid were prepared, and their glycidylic derivatives, M-1 and M-2, respectively, were obtained through the reaction of the carboxylic group with epichlorohydrin. The ring opening of benzoxazine and epoxy took place simultaneously with no catalyst for both monomers. Likewise, both ring-opening polymerizations took place when boron trifluoride monoethylamine (BF3·MEA) or 4-(N,N-dimethylamino)pyridine was used as a catalyst for M-1. However, for M-2, when BF3·MEA was used as a catalyst, the epoxy and benzoxazine ring openings could be distinguished, and a polyether intermediate containing benzoxazine side chains could be obtained.

  2. Rapid Communications

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Note
    1. Main-chain ionene polymers based on trans-1,2-bis(4-pyridyl)ethylene exhibiting both thermotropic liquid-crystalline and light-emitting properties (pages 1541–1554)

      Haesook Han, Paul R. Vantine, Alexi K. Nedeltchev and Pradip K. Bhowmik

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21259

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      Several ionene polymers with organic counterions were prepared by either the quaternization reaction of trans-1,2-bis(4-pyridyl)ethylene with oligo(ethylene glycol)-p-ditosylates in methanol or the metathesis reaction in water. They were characterized for their thermotropic liquid-crystalline and light-emitting properties with various experimental techniques.

    2. Transition-metal-catalyzed conjugated polymers of 1,6-heptadiyne derivatives in supercritical carbon dioxide (pages 1555–1560)

      B. Vijaya Kumar Naidu, Bang-Hee Oh, Dong-Hee Nam, Chan-Koo Hwang, Sung-Ho Jin, Kwon-Taek Lim, Ha-Soo Hwang, Jae Wook Lee and Yeong-Soon Gal

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21248

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      We investigated the polymerization of semifluorinated 1,6-heptadiyne derivatives with MoCl5 as a catalyst in a supercritical carbon dioxide medium for the first time. The weight-average molecular weight and polydispersity of the resulting polymers were in the ranges of 11.7–107.2 × 103 and 1.3–6.7, respectively. The 13C NMR spectrum of the polymers confirmed the five-membered ring structure.

  3. Note

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Note
    1. You have free access to this content
      Preparation of carbonated natural rubber (pages 1561–1567)

      Seiichi Kawahara and Takayuki Saito

      Article first published online: 12 JAN 2006 | DOI: 10.1002/pola.21282

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      Carbonated natural rubber was prepared from deproteinized natural rubber with supercritical carbon dioxide, in which the deproteinization of natural rubber was performed in the latex stage with urea in the presence of a surfactant. The deproteinized natural rubber was epoxidized with peracetic acid in the latex stage, and this was followed by depolymerization with peroxide to prepare liquid epoxidized natural rubber. The liquid epoxidized rubber was incubated with supercritical carbon dioxide with lithium bromide as a catalyst at various temperatures and pressures. The product was proved to be carbonated natural rubber by means of Fourier transform infrared, 1H NMR, 13C NMR, two-dimensional 1H–1H correlation, two-dimensional 1H–13C correlation, and two-dimensional heteronuclear multiple bond correlation.

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