Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 43 Issue 19

1 October 2005

Volume 43, Issue 19

Pages 4323–4673

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      Hybrid metal–polymer composites from functional block copolymers (pages 4323–4336)

      Robert B. Grubbs

      Version of Record online: 11 AUG 2005 | DOI: 10.1002/pola.20946

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      This highlight focuses on the use of functional block copolymers for the localization of metals, especially metallic nanoparticles, on the nanometer scale through block copolymer phase segregation. Research from the author's group on the use of alkyne-functional block copolymers for the preparation of cobalt-containing materials is discussed in this context.

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    1. Water-soluble poly(ethylene oxide)-block-poly(p-phenylene vinylene) copolymer: Synthesis and characterization (pages 4337–4350)

      Catherine Bianchi, Bruno Grassl, Bernard François and Christine Dagron-Lartigau

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20903

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      Water-soluble and photoluminescent block copolymers [poly(ethylene oxide)-block-poly(p-phenylene vinylene) (PEO-b-PPV)] were synthesized, in two steps, from α-halo-α′-alkylsulfinyl-p-xylene and activated poly(ethylene oxide) (PEO) chains in tetrahydrofuran at 25 °C. This copolymerization led to unreacted PEO chains mixed with partly converted PEO-b-PPV, which could be fully converted thermally. Different monomers and reaction conditions, such as the order of reagent addition and the addition of an extra base, were studied. These results were examined, as well as the anionic copolymerization mechanism and the photoluminescence behavior in tetrahydrofuran and water solutions.

    2. Multi-center nature of heterogeneous Ziegler–Natta catalysts: TREF confirmation (pages 4351–4362)

      Yury V. Kissin, Francis M. Mirabella and Craig C. Meverden

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20875

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      A Tref curve of ethylene/1-butene copolymer prepared with a Ti-based supported Ziegler–Natta catalyst and its resolution into Lorentz components.

    3. Synthesis and characterization of thermally stable sulfonated polybenzimidazoles obtained from 3,3′-disulfonyl-4,4′-dicarboxyldiphenylsulfone (pages 4363–4372)

      Shengbo Qing, Wei Huang and Deyue Yan

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20842

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      A novel sulfonated aromatic diacid, 3,3′-disulfonyl-4,4′-dicarboxyldiphenylsulfone (DSDCDPS), was successfully synthesized from 4,4′-dimethyldiphenylsulfone by sulfonation and further oxidation. A series of sulfonated polybenzimidazoles (sPBI-SS) with various sulfonation degrees was prepared from DSDCDPS, 4,4′-sulfonyldibenzoic acid and 3,3′-diaminobenzidine by solution copolycondensation in poly(phosphoric acid). The DSDCDPS-based sPBI-SS with the number-average molecular weights of 32,000–55,000 were easy to dissolve in DMF, DMSO, and DMAc, and could be cast into transparent, tough, and flexible membranes. The membranes exhibited good thermal stabilities, high storage moduli, and mechanical properties, in addition to high glass transition temperatures and low swelling degrees.

    4. Star-shaped polystyrenes with glycoconjugated periphery and interior: Synthesis and entrapment of hydrophilic molecule (pages 4373–4381)

      Atsushi Narumi, Shin Yamane, Yutaka Miura, Harumi Kaga, Toshifumi Satoh and Toyoji Kakuchi

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20847

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      Star-shaped polystyrenes with glucose in the periphery and interior were synthesized via 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated living radical polymerizations. The polymers were found to entrap a hydrophilic molecule at their glycoconjugated periphery or interior in the good solvent for polystyrene.

    5. Poly(styrene-co-glycerol dimethacrylate): Synthesis, characterization, and application as a resin for gel-phase peptide synthesis (pages 4382–4392)

      Michael Roice and V. N. Rajasekharan Pillai

      Version of Record online: 25 AUG 2005 | DOI: 10.1002/pola.20917

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      GDMA-PS, a new flexible cross-linked styrene-based polymer, has been synthesized by free radical suspension polymerization. The application of GDMA-PS as a support for peptide synthesis is demonstrated by synthesizing the 65–74 fragment of ACP and compared with TentaGel™ resin.

    6. Ring-opening polymerizations of propylene oxide by double metal cyanide catalysts prepared with ZnX2 (X = F, Cl, Br, or I) (pages 4393–4404)

      Il Kim, Seung Hoon Byun and Chang-Sik Ha

      Version of Record online: 25 AUG 2005 | DOI: 10.1002/pola.20914

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      Polymerizations of propylene oxide were carried out with double metal cyanide (DMC) catalysts based on Zn3[Co(CN)6]2. Through the control of the type and amount of ZnX2 (X = F, Cl, Br, or I) during the preparation of the catalyst, the catalytic activity, induction period, and unsaturation level in the polyether polyols could be tuned. ZnBr2 was the most effective zinc salt with respect to the properties of the resulting polymers as well as the activity and induction period. The DMC catalysts produced polyoxypropylenes with an ultralow unsaturation level (0.0025–0.0057 mequiv/g) and a narrow molecular weight distribution (1.07–1.42) without high-molecular-weight tails; this resulted in a low viscosity (962–3950 cP).

    7. Anionic polymerization of methyl methacrylate by initiating systems based on lithium amides of various secondary amines (pages 4405–4411)

      Eiji Ihara, Naohiro Omura, Shinsuke Tanaka, Tomomichi Itoh and Kenzo Inoue

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20912

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      The anionic polymerization of methyl methacrylate in toluene at −78 °C with lithium amides of various secondary amines (diisopropylamine, N-isopropylaniline, N-n-butylaniline, indoline, and N-ethyl-o-toluidine) as initiators was studied. The tacticity of the resulting poly(methyl methacrylate)s (PMMAs) was dependent on the kind of secondary amine, and highly isotactic PMMAs (91–93% mm) were obtained when lithium amides of N-isopropylaniline and N-n-butylaniline were employed. The isotacticity of the PMMAs further increased up to 98% mm with initiating systems composed of the lithium amides, n-butyllithium, and transition-metal halides (WCl6, MoCl5, and NbCl5).

    8. Synthesis of new photoresponsive polyesters containing norbornadiene moieties by the ring-opening copolymerization of donor–acceptor norbornadiene dicarboxylic acid anhydride with donor–acceptor norbornadiene dicarboxylic acid monoglycidyl ester derivatives (pages 4412–4421)

      Yoshitomo Ono, Naoyuki Kawashima, Hiroto Kudo, Tadatomi Nishikubo and Takabumi Nagai

      Version of Record online: 25 AUG 2005 | DOI: 10.1002/pola.20911

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      The ring-opening copolymerization of donor–acceptor norbornadiene (D–A NBD) dicarboxylic acid monoglycidyl ester derivatives with D–A NBD dicarboxylic acid anhydride was performed with tetraphenylphosphonium bromide as a catalyst in toluene to produce new norbornadiene (NBD) polyesters containing D–A NBD moieties in the main chain and in the side chain in one step in good yields. The photoisomerization of the D–A NBD moieties in these polyesters proceeded very smoothly to give the corresponding quadricyclane groups. Because these NBD polyesters contained many NBD moieties in the polymer chain, they had the highest capacity for heat storage in the D–A NBD polymers reported so far. The stored thermal energy of the irradiated polyesters was evaluated by differential scanning calorimetry analysis to be approximately 150–190 J/g.

    9. A novel cyclic dithiocarbonate having siloxane moiety; Approach to curable siloxane oligomer (pages 4422–4430)

      Kazuya Uenishi, Atsushi Sudo and Takeshi Endo

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20921

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      A novel 5-membered cyclic dithiocarbonate (DTC) having a siloxane moiety was successfully synthesized from the corresponding epoxide precursor by its cycloaddition with carbon disulfide. Selective condensation of the siloxane part gave the corresponding oligomer having DTC pendant. The oligomer was cured with amines under mild condition.

    10. Synthesis and characterization of poly[styrene-b-methyl(3,3,3-trifluoropropyl)siloxane] diblock copolymers via anionic polymerization (pages 4431–4438)

      Lingmin Yi, Xiaoli Zhan, Fengqiu Chen, Feng Du and Linbing Huang

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20927

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      A series of narrow molecular weight distribution polystyrene-b-poly[methyl(3,3,3-trifluoropropyl)siloxane] (PS-b-PMTFPS) diblock copolymers were synthesized by the sequential anionic polymerization of styrene and trans-1,3,5-trimethyl-1,3,5-tris(3′,3′,3′-trifluoropropyl)cyclotrisiloxane in tetrahydrofuran (THF) with n-butyllithium (n-BuLi) as the initiator. The back-biting by the chain ends and the redistribution reactions between siloxane units of the poly [methyl(3,3,3-trifluoropropyl)siloxane] block chains were suppressed under appropriate polymerization conditions.

    11. Synthesis and properties of polyimide ionomers containing sulfoalkoxy and fluorenyl groups (pages 4439–4445)

      Tomohiro Yasuda, Kenji Miyatake, Michiko Hirai, Masato Nanasawa and Masahiro Watanabe

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20843

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      A series of sulfopropylated and sulfobutylated polyimide copolymers containing fluorenyl groups, SPI-4, were synthesized. SPI-4 showed much better hydrolytic stability than the main-chain sulfonated polyimides. At high relative humidity all the SPI-4 membranes showed high mechanical properties (>34 MPa of the maximum stress) and proton conductivity (>0.1 Scm−1). These properties are comparable to or even better than those of the perfluorosulfonic acid ionomer (Nafion 112). The new polyimide ionomers have proved to be a possible candidate as polymer electrolyte membrane for PEFCs and DMFCs.

    12. Atom transfer radical polymerization of sodium2-acrylamido-2-methylpropanesulfonate (pages 4446–4454)

      Giancarlo Masci, Laura Giacomelli and Vittorio Crescenzi

      Version of Record online: 12 AUG 2005 | DOI: 10.1002/pola.20913

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      The first example of well-controlled atom transfer radical polymerization (ATRP) of a permanently charged anionic acrylamide monomer is reported. ATRP of sodium 2-acrylamido-2-methylpropanesulfonate (NaAMPS) was achieved with ethyl 2-chloropropionate (ECP) as an initiator and the CuCl/CuCl2/tris(2-dimethylaminoethyl)amine (Me6TREN) catalytic system. The polymerizations were carried out in 50:50 (v/v) N,N-dimethylformamide (DMF)/water mixtures at 20 °C. Polydispersities as low as 1.11 were obtained. Block copolymers with N,N-dimethylacrylamide and N-isopropylacrylamide were also prepared. The use of a DMF/water mixed solvent should make possible the synthesis of new amphiphilic ionic block copolymers without the use of protecting group chemistry.

    13. Synthesis, characterization, and hyperpolarizability measurements of main-chain azobenzene molecules (pages 4455–4468)

      P. Smitha, S. K. Asha and C. K. S. Pillai

      Version of Record online: 15 AUG 2005 | DOI: 10.1002/pola.20922

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      AB type azobenzene monomers exhibit increasing first order molecular hyperpolarizability β values with increase in the ring size of the donor segment. Comparing S-6 and S-7, based on α and β isomers of naphthol, respectively, S-6 had the highest and S-7 the lowest β values brought about by tautomerism assisted by intramolecular hydrogen bonding in the latter.

    14. Synthesis and characterization of poly(imide-urethane) based on novel chain-extender containing both imide and sulphone functions (pages 4469–4477)

      XiuMin Qin, XiaoHui Yang, XinLing Wang and MingJun Wang

      Version of Record online: 15 AUG 2005 | DOI: 10.1002/pola.20920

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      Several new glycols containing both imide and sulphone groups were prepared and were used as chain extender to obtain a series of thermoplastic poly(imide-urethane)s. Because of the introduction of imide rings into the backbones, the poly(imide-urethane)s exhibited better thermal stabilities and mechanical properties than did conventional linear polyurethane.

    15. Synthesis, structure, and characterization of nematic liquid-crystalline thermosets based on bisacrylates (pages 4478–4485)

      Jian-She Hu, Bao-Yan Zhang, Dan-Shu Yao, Wen-Qiang Xiao and Yan-Li Dong

      Version of Record online: 15 AUG 2005 | DOI: 10.1002/pola.20924

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      Four difunctional monomers (M1M4) and their corresponding series of liquid-crystalline thermosets (LCTs) were prepared and characterized. The mesomorphic properties and thermal stability were investigated with differential scanning calorimetry, thermogravimetric analysis, polarized optical microscopy, and X-ray diffraction. M1M4 and four series of LCTs showed a nematic phase until thermal decomposition. Monomers with higher rigidity of the mesogenic core had higher melting temperatures and faster curing reaction rates, and their corresponding LCTs had higher glass-transition temperatures and thermal stability. Moreover, the glass-transition temperatures and thermal stability of LCTs increased with the curing temperature and time.

    16. Enhancement of color purity in blue light emitting poly(fluorene)s and poly(p-phenylene)s with 2,6-distyrylpyridine kinked segments along the backbone (pages 4486–4495)

      John A. Mikroyannidis and Aristomenis V. Kazantzis

      Version of Record online: 15 AUG 2005 | DOI: 10.1002/pola.20923

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      Two new series of soluble random or alternating polyfluorenes and poly-p-phenylenes were prepared by Suzuki coupling, utilizing 2,6-bis(4-distyrylpyridine) as a comonomer. The kinked structure of this comonomer depressed the aggregation tendency and enhanced the color purity of the blue emitting polyfluorenes. In addition, the emitted light color of these polymers in solution and in solid state could be reversibly changed between blue and green by the protonation–deprotonation process of the pyridine ring.

    17. Bulk properties of dendronized polymers with tailored end-groups emanating from the same backbone (pages 4496–4504)

      Andreas M. Nyström, István Furó, Eva Malmström and Anders Hult

      Version of Record online: 15 AUG 2005 | DOI: 10.1002/pola.20918

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      The bulk properties of three sets of dendronized polymers based on 2,2-bis(methylol)propionic acid (bis-MPA) with hydroxyl, acetonide, and aliphatic hexadecyl end-groups have been investigated. The materials were investigated by dynamic melt rheology, differential scanning calorimetry (DSC), size exclusion chromatography (SEC), and 1H NMR self-diffusion techniques.

    18. Solvent effects in the polymerization of propylene catalyzed by octahedral complexes (pages 4505–4516)

      Victoria Volkis, Elena Smolensky, Anatoli Lisovskii and Moris S. Eisen

      Version of Record online: 19 AUG 2005 | DOI: 10.1002/pola.20915

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      The effect of solvents [toluene, dichloromethane (DCM), hexane, and plain propylene] was studied on the polymerization of propylene with the octahedral complexes bis(trimethylsilyl)benzamidinate titanium dichloride (A), bis(acetylacetonate) titanium dichloride (B), and bis(diethylamino) titanium di-2-(diphenylphosphanylamino)pyridine (C) as catalytic precursors activated by methylalumoxane.

    19. Synthesis and properties of new poly(terfluorene) derivatives containing spirobifluorene and electron transport groups for stable blue electroluminescence (pages 4517–4529)

      Bing Huang, Jun Li, Lianqing Chen, Jingui Qin, Chong'an Di, Gui Yu and Yunqi Liu

      Version of Record online: 16 AUG 2005 | DOI: 10.1002/pola.20919

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      Three new blue-emitting poly(terfluorene) derivatives containing spirobifluorene and electron-transport groups (quinoline or oxadiazole), which effectively tunes the emission bands and reduces LUMO energy levels, have been prepared by Suzuki coupling reaction. All the polymers show excellent thermal spectral stability. Stable blue electroluminescence with narrow emission was achieved in the devices of ITO/PEDOT/polymer/Ca/Al.

    20. Polymerization of substituted acetylenes by various rhodium catalysts: Comparison of catalyst activity and effect of additives (pages 4530–4536)

      Atsushi Nakazato, Irfan Saeed, Toru Katsumata, Masashi Shiotsuki, Toshio Masuda, Jiri Zednik and Jiri Vohlidal

      Version of Record online: 16 AUG 2005 | DOI: 10.1002/pola.20934

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      Polymerizations of monosubstituted acetylenes, i.e., phenylacetylene (5a), t-butylacetylene (5b), N-propargylhexanamide (5c), and n-hexyl propiolate (5d) were examined with [Rh(nbd)Cl]2 (1), [Rh(cod)(O-o-cresol)]2 (2), Rh+(nbd)[(η6-C6H5)B-(C6H5)3] (3), and Rh-vinyl complex (4) so as to compare their catalytic activity. The catalytic activity tended to decrease in the order of 3 > 4 > 2 > 1. In the polymerization of 5a, by the 1/amine systems, both polymerization rate and polymer molecular weight increased with increasing basicity of amines.

    21. Evaluation of long-term performance of antioxidants using prooxidants instead of thermal acceleration (pages 4537–4546)

      Lina Burman and Ann-Christine Albertsson

      Version of Record online: 16 AUG 2005 | DOI: 10.1002/pola.20936

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      Evaluation of stabilization efficiencies of different antioxidants in polymers at low temperature and relatively short time was performed using incorporation of a prooxidant for catalytic oxidation. Comparisons were made between polypropylene films stabilized with primary antioxidants and with or without the prooxidant manganese stearate at different temperatures. The relative efficiency of the antioxidants at prooxidant acceleration correlated better to low temperature long-term test than at the thermal acceleration. Differences in the amounts of the antioxidants present after the processing of the films were corrected for by normalization from the exponential decrease in the amount of antioxidant in the film. The fastest comparison of the antioxidants efficiency was obtained from oxidation induction times using total luminescence intensity measurements.

    22. Conducting polythiophenes with a broad spectrum of reactive groups (pages 4547–4558)

      Guangtao Li, Sheshanath Bhosale, Shengyang Tao, Sidhanath Bhosale and Jurgen-Hinrich Fuhrhop

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20928

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      The development of reliable and reproducible chemistries for the immobilization of biomolecules to a conducting polymer (CP) is a key challenge in the design and preparation of a CP-based biosensor. In this article, a series of new conducting polythiophenes functionalized with the most used reactive groups in immobilization chemistry are described.

    23. Optically high transparency and light color of organosoluble polyamides containing trifluoromethyl and kink diphenylmethylene linkage (pages 4559–4569)

      Der-Jang Liaw

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20782

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      New polyamides were prepared directly from a diamine containing an electron-withdrawing trifluoromethyl group and a kink diphenylmethylene linkage with various dicarboxylic acids. All the polyamides showed outstanding solubility. The films had relatively low dielectric constants in the range of 3.37–3.87 (100 KHz). A low coefficient of thermal expansion for the polyamides was observed in the range of 54–78 ppm/°C (by thermomechanical analysis). These polyamides showed excellent thermal stability, and the 10% weight loss temperatures were in the range of 484–507 in N2. The polymers had an initial modulus of 1.8–2.2 GPa. The polyamides afforded light-color polymer films with high transmittance in the visible region (400–700 nm), and their cutoff wavelength was lower than 362 nm.

    24. Aromatic polyesters from naturally occurring monosaccharides: Poly(ethylene terephthalate) and poly(ethylene isophthalate) analogs derived from D-mannitol and galactitol (pages 4570–4577)

      Francisca Zamora, Khalid Hakkou, Abdelilah Alla, Manuel Rivas, Isaac Roffé, Manuel Mancera, Sebastián Muñoz-Guerra and Juan A. Galbis

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20933

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      A series of new aromatic polyesters were obtained by polycondensation reaction of the terephthaloyl chloride (T) or isophthaloyl chloride (I) and 2,3,4,5-tetra-O-methyl-D-mannitol (M) or 2,3,4,5-tetra-O-methyl-galactitol (G) in o-dichlorobenzene. They were soluble in chloroform, but insoluble in water and other polar oxygenated solvents. However, they showed a notable hygroscopicity, lower for those containing isophthalic units. DSC and X-ray diffraction studies showed that D-mannitol-based polyesters were stiffer and less crystalline than those derived from galactitol, which presented a noticeably lower thermal stability.

    25. Effective fixation of carbon dioxide into poly(glycidyl methacrylate) in the presence of pyrrolidone polymers (pages 4578–4585)

      Shin-Ichi Yamamoto, Katsuyuki Kawabata, Osamu Moriya and Takeshi Endo

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20943

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      Copolymers of glycidyl methacrylate (GMA) with N-vinyl-2-pyrrolidone were prepared under radical conditions and employed for the fixation of CO2 with LiBr as a catalyst. The conversion of oxirane groups to carbonate by the fixation of CO2 increased remarkably in comparison with the homopolymer of GMA (PGMA), whereas the polymer blends of PGMA with the homopolymer of N-vinyl-2-pyrrolidone fixed CO2 to give the cyclic carbonate polymer quantitatively. In both cases, the reaction proceeded even in a dilute reaction system. Furthermore, the fixation of CO2 was enabled under solvent-free conditions.

    26. Molecular dynamics of star-shaped poly(L-lactide)s in tetrahydrofuran as solvent monitored by fluorescence spectroscopy (pages 4586–4599)

      Martin Danko, Jan Libiszowski, Tadeusz Biela, Marian Wolszczak and Andrzej Duda

      Version of Record online: 24 AUG 2005 | DOI: 10.1002/pola.20932

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      Linear telechelic, α,ω-ditelechelic, and star-shaped tri-, tetra-, penta-, and hexa-arm poly(L-lactide)s (PLAs) fitted at every arm with pyrene end group have been prepared. Internal dynamics and mobility of the PLA chains in THF solution at 25 °C, with regard to the number of PLA arms in one macromolecule and the individual arm average degree of polymerization, was followed by fluorescence spectroscopy. Analysis of both static and time-resolved spectra of the star-shaped polymers revealed dynamic segmental motion resulting in end-to-end cyclization, accompanied by an excimer formation. Probability and rate of the latter reaction increased with increasing number of arms and with decreasing their polymerization degree. Moreover, time-resolved measurements clearly show that increasing of the number of arms leads to their stretching away from the center of the star-shaped PLA macromolecule.

    27. Synthesis of soluble electron-donating polymers containing vinylogous TTF by oxidative dimerization of 1,4-bisdithiafulvenyl-2,5-dialkoxybenzene (pages 4600–4608)

      Kensuke Naka, Shinsuke Inagi and Yoshiki Chujo

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20938

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      A high molecular weight electron donating polymer containing vinylogous TTF was synthesized by chemical oxidative polymerization of 1,4-bis(dithiafulvenyl)-2,5-didodecyloxybenzene. The obtained polymer was soluble in CH2Cl2, CHCl3, and toluene.

    28. Synthesis and properties of highly branched polycations with an aliphatic polyether scaffold (pages 4609–4617)

      Ernst Schwab and Stefan Mecking

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20983

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      A series of well-defined hyperbranched cationic polyelectrolytes with pyridinium and 1,2-dimethylimidazolium functionalities based on a hyperbranched polyglycerol scaffold with a narrow polydispersity were prepared by a polymer analogous reaction in a one-pot synthesis. The density and flexibility of the charged moieties, evidenced by the glass-transition temperature, could be conveniently varied by spacer length n. The polyelectrolytes were thermally stable up to 200–300 °C. Their solubility was strongly influenced by the nature of the counterions.

    29. Synthesis and characterization of poly(2-ethylhexyl methacrylate) copolymers containing pendant, self-complementary multiple-hydrogen-bonding sites (pages 4618–4631)

      Casey L. Elkins, Taigyoo Park, Matthew G. McKee and Timothy E. Long

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20961

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      The synthesis and characterization of copolymers containing 2-ethylhexyl methacrylate and a quadruple-hydrogen-bonding site, 2-ureido-4[1H]-pyrimidone methacrylate (UPyMA), are described. An analogous dimeric hydrogen-bond-containing copolymer based on 2-ethylhexyl methacrylate and methacrylic acid (PEHMA-co-MAA) was also synthesized for comparative purposes. Creep compliance measurements as a function of temperature indicated a decrease in the creep compliance with increasing UPyMA content over the range of 1–10 mol % UPyMA. Melt rheological analysis also showed an increase and lengthening of the plateau modulus as a function of frequency with increasing UPyMA content, as well as increasing complex viscosity as a function of temperature.

    30. Ethylene and 1-hexene copolymerization with CO-prereduced phillips CrOx/SiO2 catalyst in the presence of Al–alkyl cocatalyst (pages 4632–4641)

      Yuwei Fang, Boping Liu, Kouichi Hasebe and Minoru Terano

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20935

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      Ethylene and 1-hexene copolymerization with Phillips CrOx/SiO2 catalyst prereduced by CO was carried out in the presence of triethyl aluminum (TEA) cocatalyst. A hybrid-type kinetics indicated that there existed two types of active sites, named as site A and site B, in the catalyst system. Site A with instant activation, high activity, and fast decay was transformed from a metathesis site, Cr(II) site coordinated with CO or CO2, which contributed to the in situ formation of short α-olefins resulting in short chain branching, especially methyl branching. TEA cocatalyst can transform this metathesis site into polymerization site through the desorption of CO or CO2 from the Cr(II) site. Site B with slow activation, relatively low activity, and slow decay was generated through the reduction of residual chromate(VI) by TEA cocatalyst.

  3. Aritcles

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    1. Synthesis of photocrosslinkable hyperbranched polyesters and their film properties (pages 4642–4653)

      Ken Maruyama, Hiroto Kudo, Takayuki Ikehara, Nobuhito Ito and Tadatomi Nishikubo

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20957

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      The synthesis and photoreactivity of hyperbranched polyesters with terminal methacryloyl groups (HBPEAc) and their cured film properties were examined. HBPEAc samples were prepared by the polyaddition of bisphenol A diglycidyl ether with trimesic acid and methacrylic acid with quaternary onium salts as catalysts. The photoradical polymerization of the obtained HBPEAc was examined in the presence of a photoinitiator in the film state upon UV irradiation, and the photoradical polymerization proceeded smoothly to give insoluble cured films. Furthermore, an alkaline-developable hyperbranched polyester containing pendant carboxyl groups (HBPEAc-COOH) was synthesized by the addition reaction of HBPEAc with cis-1,2,3,6-tetrahydrophthalic anhydride, and the patterning properties of the obtained HBPEAc-COOH were examined. The birefringence of cured HBPEAc was also examined, and it was found that the cured HBPEAc film did not have birefringence.

  4. Articles

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    1. New synthetic methods for the formation of basic, polyvalent, hyperbranched grafts (pages 4654–4665)

      David E. Bergbreiter, Eric E. Simanek and Izabela Owsik

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20916

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      A practical route to polybasic, polyamine, hyperbranched grafts using polyethyleneimine (PEI) and cyanuric chloride as a coupling agent is described. Grafts with 1.00 and 0.17 mmol of base/g of solid were prepared on silica gel and on polyethylene powder and were characterized by XPS spectroscopy, TGA analysis, ATR-IR spectroscopy, acid–base titration, and by 13C CP-MAS NMR spectroscopy. [A color version of the adjacent figure given can be viewed online issue, which is available at www.interscience.wiley.com.]

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    1. Binary copolymer reactivity of tert-butyl methacrylate, 2-(N,N-dimethylamino)ethyl methacrylate, solketal methacrylate, and 2-bromoethyl methacrylate (pages 4666–4669)

      Larissa N. Miranda and Warren T. Ford

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20939

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      The reactivity ratios for radical copolymerization of five binary combinat ions of tert-butyl methacrylate (tBMA), 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA), and solketal methacrylate ((2,2-dimethyl-1,3-dioxolan-4-yl)methyl methacrylate, SMA), and 2-bromoethyl methacrylate (BEMA) copolymer pairs were calculated by the terminal model and the Tidwell–Mortimer nonlinear least squares method from NMR analyses of unreacted monomers of low conversion polymerizations. The results are as follows for M1, M2: tBMA, SMA, r1 = 1.40, r2 = 0.79; BEMA, tBMA, r1 = 1.15, r2 = 0.82; BEMA, SMA, r1 = 1.84, r2 = 0.71; tBMA, DMAEMA, r1 = 1.26, r2 = 0.97; DMAEMA, SMA, r1 = 1.40, r2 = 0.65.

    2. Well-defined linear multiblock and branched polypeptides by linking chemistry (pages 4670–4673)

      Thrasyvoulos Aliferis, Hermis Iatrou and Nikos Hadjichristidis

      Version of Record online: 23 AUG 2005 | DOI: 10.1002/pola.20926

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      Attempts to synthesize well-defined polypeptides by the ring-opening polymerization of the corresponding α-amino acid N-carboxyanhydrides, with primary amines as initiators, have been plagued by unwanted side reactions for more than 50 years. Recently, we have shown that the ring-opening polymerization of α-amino acid N-carboxyanhydrides with n-hexylamine, using high-vacuum techniques, leads to high-molecular-weight, well-defined living polypeptides in ∼100% yields with low polydispersity. With appropriate linking agents and high-vacuum techniques, model linear triblock and star block copolypeptides have been synthesized. The method is a general one, which can be extended to molecules with high structural complexity, which will facilitate the design of biologically active molecules.

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