Journal of Polymer Science Part A: Polymer Chemistry

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

15 February 2008

Volume 46, Issue 4

Pages 1151–1531

  1. Highlights

    1. Top of page
    2. Highlights
    3. Articles
    1. You have free access to this content
      Cyclic oligomer chemistry (pages 1151–1164)

      Daniel J. Brunelle

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22526

  2. Articles

    1. Top of page
    2. Highlights
    3. Articles
    1. Factors influencing the C[BOND]ON bond strength of the alkoxyamines in the styrene–acrylonitrile–TEMPO copolymerization system (pages 1165–1177)

      E. Megiel and A. Kaim

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22456

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      Homolytic bond dissociation energy (BDE) of the (C[BOND]ON) bond for several N-alkoxyamines derived from 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) were determined from quantum-mechanical calculations. The investigated N alkoxyamines were considered as models for dormant forms of propagating chains in the radical copolymerization process of styrene with acrylonitrile in the presence of TEMPO accroding to the terminal and penultimate model.

      A dramatically weakened C[BOND]ON bond in the alkoxyamine containing two consecutive styrene units in the propagating chain was ascribed to several geometric parameters characterizing energetically unfavorable conformation of the substituents.

    2. Surface-initiated ring-opening polymerization of p-dioxanone on Wang resin bead (pages 1178–1184)

      Hyo Jin Lee, B. Ramaraj, Soo Min Lee and Kuk Ro Yoon

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22457

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      Wang resin was treated with Sn(Oct)2 and reacted with p-dioxanone in anhydrous toluene at 80 °C. The resultant Wang-g-PPDO was washed and characterized by FTIR, DSC, TGA, OM, and SEM.

    3. Vinyl addition polymerization of norbornene using cyclopentadienylzirconium trichloride activated by isobutyl-modified methylaluminoxane (pages 1185–1191)

      Osamu Nishizawa, Hideki Misaka, Toyoji Kakuchi and Toshifumi Satoh

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22458

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      Norbornene polymerization using the commercially available and inexpensive catalyst system, cyclopentadienylzirconium trichloride (CpZrCl3) and isobutyl-modified methylaluminoxane (MMAO40/60), were carried out over a wide range of polymerization temperatures and monomer concentrations. The polymerization using the CpZrCl3/MMAO40/60 catalyst system proceeds through the vinyl addition mechanism to produce atactic polynorbornene, which was soluble in chloroform, toluene, and 1,2-dichlorobenzene, but insoluble in methanol.

    4. One-stage synthesis of narrowly dispersed polymeric core-shell microspheres (pages 1192–1202)

      Fei Wen, Wangqing Zhang, Peiwen Zheng, Xu Zhang, Xinlin Yang, Yao Wang, Xiaowei Jiang, Guanwei Wei and Linqi Shi

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22460

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      A method of one-stage soap-free emulsion polymerization to synthesize core-shell microspheres is proposed. Following this method, core-shell microspheres of poly(styrene-co-4-vinylpyridine), poly(styrene-co-methyl acrylic acid), and poly[styrene-co-2-(acetoacetoxy)ethyl methacrylate-co-methyl acrylic acid] are synthesized by one-stage soap-free emulsion polymerization of a mixture of one or two hydrophobic monomers and a suitable hydrophilic monomer.

    5. The incorporation of rigid diol monomers into poly(butylene terephthalate) via solid-state copolymerization and melt copolymerization (pages 1203–1217)

      M. A. G. Jansen, L. H. Wu, J. G. P. Goossens, G. de Wit, C. Bailly, C. E. Koning and G. Portale

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22462

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      Incorporation of 2,2-bis[4-(hydroxyethoxy)phenyl]propane (Dianol) into poly(butylene terephthalate) (PBT) via solid-state copolymerization (SSP) showed that Dianol, besides being the reactant, also acts as a swelling agent for rigid amorphous PBT segments. The thermal behavior of the resulting copolyesters is comparable with melt copolymerized (MP) copolymers, although having a different chemical microstructure. The main reason is a full melt miscibility of the different chain segments, which eliminates the advantages of a blocky microstructure for the SSP copolyesters. However, incorporation of 2,2′-biphenyldimethanol (BDM) resulted in a higher crystallization temperature, which may be related to preordering of the incorporated BDM-moieties in the melt.

    6. ABCD 4-miktoarm star quarterpolymers using click [3 + 2] reaction strategy (pages 1218–1228)

      Ozcan Altintas, Gurkan Hizal and Umit Tunca

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22463

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      Two samples of ABCD 4-miktoarm star quarterpolymer with A = polystyrene (PS), B = poly(ε-caprolactone) (PCL), C = poly(methyl methacrylate) (PMMA) or poly(tert-butyl acrylate) (PtBA), and D = poly(ethylene glycol) (PEG) were prepared using Click reaction strategy (Cu(I)-catalyzed Huisgen [3 + 2] reaction). Thus, first, predefined block copolymers of different polymerization routes, PS-b-PCL with azide and PMMA-b-PEG and PtBA-b-PEG copolymers with alkyne functionality, were synthesized and then these blocks were combined together in the presence of Cu(I)/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) as a catalyst in DMF at room temperature to give the target 4-miktoarm star quarterpolymers.

    7. New poly(ether-ester) thermosets obtained by cationic curing of DGEBA and 7,7-dimethyl-6,8-dioxaspiro[3.5] nonane-5,9-dione with several Lewis acids as initiators (pages 1229–1239)

      Lidia González, Xavier Ramis, Josep Maria Salla, Ana Mantecón and Angels Serra

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22464

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      Scandium, ytterbium, and lanthanum triflates and boron trifluoride monoethylamine were used as cationic initiators to cure a mixture 2:1 (mol/mol) of diglycidylether of bisphenol A and 7,7-dimethyl-6,8-dioxaspiro[3.5]nonane-5,9-dione. The evolution of the epoxy and lactone during curing and the linear ester groups in the final materials were evaluated by FTIR/ATR. The shrinkage on curing and the thermal degradability of the materials on varying the initiator used were evaluated. The expandable character of MCB was confirmed. The materials obtained were more degradable than conventional epoxy resins due to the tertiary ester groups incorporated in the network by copolymerization.

    8. Styrene polymerization catalyzed by metal porphyrin complex/MAO for in situ synthesizing polystyrene containing air stable π cation radicals (pages 1240–1248)

      Jianzhong Li, Min Li, Shiyun Li, Liya Shi, Changyi Ren, Dongmei Cui, Yanhui Wang and Tao Tang

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22465

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      A novel catalyst system with high thermal stability based on nickel(II) tetraphenylporphyrin and methylaluminoxane for styrene polymerization was developed. The mechanism of the polymerization was discussed and a special coordination mechanism was proposed. One electron oxidation of Ni(II)TPP forming Ni(II)TPP π cation radicals occurred in the polymerization, and the cation radicals could remain in the resulting polystyrene stably. The polystyrene product containing Ni(II)TPP π cation radicals can be used as a potential functional material.

    9. Precision synthesis of microstructures in star-shaped copolymers of ϵ-caprolactone, L-lactide, and 1,5-dioxepan-2-one (pages 1249–1264)

      Karin Odelius and Ann-Christine Albertsson

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22466

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      Star-shaped homo- and copolymers were synthesized using two different initiating systems (I) a spirocyclic tin initiator and (II) stannous octoate together with pentaerythritol ethoxylate 15/4 EO/OH, to give polymers with identical core moieties. Three monomers (ε-caprolactone, L-lactide, and 1,5-dioxepan-2-one) and two different strategies were used to synthesize the different microstructures, i.e., a more multiblock- or a block-structure. The correct choice of the monomer addition order enabled two distinct blocks to be created for the copolymers of poly(DXO-co-LLA), and poly(CL-co-LLA). For poly(CL-co-DXO), multiblock copolymers were synthesized using both systems whereas longer blocks were created with the spirocyclic tin initiator. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    10. Preparation of single-walled carbon nanotubes-induced poly(p-oxybenzoyl) crystals (pages 1265–1277)

      Kazufumi Kobashi, Jay Lomeda, Zheyi Chen, Samina Azad, Wen-Fang Hwang and James M. Tour

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22468

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      Crystallization of oligomers was applied for the preparation of single-walled carbon nanotubes (SWNTs)/poly(p-oxybenzoyl) (POB) crystals using SWNTs as a nucleating agent. Polymerization conditions were investigated to induce the crystallization of POB oligomers through SWNTs. SWNTs/POB plate-like or lozenge-shaped crystals were successfully prepared by direct polymerization of p-hydroxybenzoic acid in a mixed solvent of DMF/Py with TsCl in the presence of functionalized SWNTs. The size of the plate-like crystals were ∼200 nm to 3 μm. The crystals consisted of some layers, ∼3 nm thick plates. The obtained crystals exhibited unique morphology and high crystallinity, producing a novel SWNT/POB hybrid.

    11. Random and AB diblock copolymers of tricyclodecanemethanol urethane methacrylate with styrene: Synthesis and morphology characterization (pages 1278–1288)

      V. D. Deepak and S. K. Asha

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22469

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      Morphology change from three-dimensional honeycomb to large spherical particles in THF water solvent mixture upon a change of polymer architecture from random copolymer to diblock copolymer is discussed. Hydrogen bond induced preorganization in THF is expected to be the driving force for the observed morphology in these side chain methacrylic urethane polymers. SEM and TEM measurements in THF water solvent mixture was used for the morphology characterization in addition to FTIR spectra and DLS in THF as solvent to analyze the hydrogen bond-induced preorganization. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    12. Synthesis and characterization of novel photoisomerizable liquid crystalline polymers containing cinnamoyl groups (pages 1289–1304)

      Po-Chih Yang and Jui-Hsiang Liu

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22470

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      A series of room temperature available novel side chain liquid crystalline polymers with thermal stable segments have been developed to overcome the defects of the thermal instability of azobenzene. The photoisomerization and thermal stability of the C[DOUBLE BOND]C segment in polymers were demonstrated. The pitch length (about 574 nm) of the cholesteric polymeric film (CP2) was estimated using SEM. The thermal stability of the Z-structural segment was confirmed by heating the polymer at 50 °C for over 5 h.

    13. Synthesis of conjugated polymers with pendant ruthenium terpyridine trithiocyanato complexes and their applications in heterojunction photovoltaic cells (pages 1305–1317)

      Kai Wing Cheng, Chris S. C. Mak, Wai Kin Chan, Alan Man Ching Ng and Aleksandra B. Djurišić

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22471

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      The photovoltaic properties of the devices fabricated from conjugated polymers with pendant trithiocyanato ruthenium terpyridine complexes. The polymers exhibit very broad absorption band spanning from 400 to 750 nm. The hole carrier mobilities of the polymers were estimated by space charge limited current modeling, which are in the order of 10−4 cm2 V−1 s−1. The power conversion efficiencies of the devices are in the range between 0.084–0.12%. Plot of incident photon to charge efficiency as the function of wavelength suggests that absorption by both conjugated main chain and ruthenium complex are essential to the photocurrent generation.

    14. A new strategy to characterize the extent of reaction of thermoset elastomers (pages 1318–1328)

      Antonio R. Webb, Jian Yang and Guillermo A. Ameer

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22472

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      A new method for determining the extent of reaction of crosslinked thermoset elastomers was developed. This method, based on the molecular weight between crosslinks as measured by equilibrium swelling, was used to examine the relationship between mechanical properties, extent of reaction, and molecular weight between crosslinks of poly(1,8-octanediol-co-citrate), a novel biodegradable thermoset elastomer.

    15. Photoinitiated dispersion polymerization of methyl methacrylate: A quick approach to prepare polymer microspheres with narrow size distribution (pages 1329–1338)

      Jia Chen, Zhaohua Zeng, Jianwen Yang and Yonglie Chen

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22473

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      PMMA microspheres with narrow side distribution have been prepared by photoinitiated dispersion polymerization. 93.7% of conversion was achieved within 30 min of UV irradiation at room temperature. The effects of various reaction parameters, including stabilizer concentration, medium composition, monomer concentration, and initiator concentration on the morphology, size, and size distribution of the microspheres were investigated. Solvency of reaction medium toward stabilizer, which affects the adsorption of stabilizer on the particle surface, was shown to be crucial for controlling particle size and uniformity because of the high reaction rate in photoinitiated dispersion polymerization.

    16. Synthesis and thiol–ene photopolymerization of allyl-ether functionalized dendrimers (pages 1339–1348)

      Camilla Nilsson, Neil Simpson, Michael Malkoch, Mats Johansson and Eva Malmström

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22474

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      Well-defined, allyl-ether functional, first-generation dendrimers have been synthesized and were crosslinked by thiol–ene chemistry, using a multifunctional thiol, TriThiol, to give clear and smooth films. The photopolymerization was conducted in the presence of a photoinitiator and no traces of either allyl-ether groups or thiols were observed by FT-Raman after cure. All crosslinked films were characterized with respect to mechanical and thermal properties. It was found that homogeneous networks were formed and that the core functionality and structure had little effect on the network properties.

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      Conjugated polymers containing electron-transporting, hole-transporting, and light-emitting units in the polymer main chain (pages 1349–1356)

      Yaqin Fu, Minghao Sun, Yonggang Wu, Zhishan Bo and Dongge Ma

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22475

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      Two kinds of pn alternating conjugated polymers and one kind of conjugated polymer containing p-type carbazole unit, n-type oxadiazole unit, and spirobifluorene unit have been prepared via Suzuki polycondensation. Electrochemical studies showed that the introducing of spirobifluorene unit in the polymer main chains could markedly increase the effective conjugation length and thus improve the electrochemical stability and the electron- and hole-injecting abilities. The electroluminescent results also showed that the introducing of spirobifluorene units could significantly improve the device performance.

    18. Highly absorbing superabsorbent polymer (pages 1357–1364)

      Thilini K. Mudiyanselage and Douglas C. Neckers

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22476

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      Highly efficient superabsorbent polymers (SAPs) were prepared via inverse suspension polymerization. The SAP particles consist of a hydrophilic core and a hydrophobic shell. This core-shell structure has enhanced their superabsorbing properties. Yellow granular superabsorbents obtained by polymerization of 50% partially neutralized acrylic acid with acrylamide (AM) using N,N′-methylene bisacrylamide (BIS) as a cross-linker and bis(methacryloylamino)-azobenzene (AC) as a surface cross-linker demonstrate excellent water absorption capacity (nearly 2500 g/g of sample).

    19. Dispersion polymerization of MMA in supercritical CO2 stabilized by random copolymers of 1H,1H–perfluorooctyl methacrylate and 2-(dimethylaminoethyl methacrylate) (pages 1365–1375)

      Ha Soo Hwang, Haldorai Yuvaraj, Won Soo Kim, Won-Ki Lee, Yeong-Soon Gal and Kwon Taek Lim

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22477

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      It is demonstrated that random copolymers composed of 1H, 1H-perfluorooctyl methacrylate (FOMA) and 2-dimethylaminoethyl methacrylate (DMAEMA) provide abnormally large stabilization on the dispersion polymerization of MMA in supercritical carbon dioxide with very low FOMA content, that is comparable with previous random copolymeric stabilizers, which need larger amount of expensive fluorous monomers. DMAEMA units having low Tg and CO2 favorable side chain contribute both on the CO2-philicity and anchoring capability of the copolymers. Although copolymeric stabilizers were not soluble in the medium entire the reaction, free-flowing spherical PMMA particles could be obtained from the polymerization.

    20. Alkyl side chain driven tunable red–yellow–green emission: Investigation on the new π-conjugated polymers comprising of 2,7-carbazole unit and 2,1,3-benzo-thiadiazole units with different side chains (pages 1376–1387)

      Junping Du, Erjian Xu, Hongliang Zhong, Feng Yu, Chang Liu, Huanrong Wu, Danli Zeng, Shijie Ren, Jing Sun, Yingchun Liu, Amin Cao and Qiang Fang

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22478

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      The polymers comprised of a 2,7-carbazole unit and a 2,1,3-benzothiadiazole showed PL emission in the solid state from green to red only by variation of the size of the substituent groups at 5-position of benzothiadiazole unit; such obvious change of emission color exhibited that the tunablity of color for conjugated polymers could be facilely realized.

    21. Synthesis and micellization of star-like hyperbranched polymer with poly(ethylene oxide) and poly(ε-caprolactone) arms (pages 1388–1401)

      Huan-Bing Wang, Xue-Si Chen and Cai-Yuan Pan

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22479

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      Star-like hyperbranched polymers with hydrophilic PEO and hydrophobic PCL have been synthesized by combination of Michael addition polymerization and surface modification. The resultant polymers displayed unimolecular micelles with hyperbranched poly(amido amine) core, and PEO and PCL as shell in DMSO. The relative amount of shell PEO to PCL in the copolymers affects their morphology in the solvents, and they had different morphologies in chloroform and deionized water. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    22. The effect of γ-cyclodextrin addition in the self-assembly behavior of pyrene labeled poly(acrylic) acid with different chain sizes (pages 1402–1415)

      Telma Costa and J. S. Seixas de Melo

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22480

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      The photophysics of poly(acrylic acid) polymers (PAA) of low- (2000 g/mol) and high- (450,000 g/mol) molecular weight (MW) hydrophobically modified with pyrene (PAAMePy) interacting with β- and γ-cyclodextrins (β-CD, γ-CD) was investigated with fluorescence techniques. A different behaviour was observed depending on the size and degree of labeling of the polymers.

    23. Atom transfer radical polymerization of methyl methacrylate catalyzed by ion exchange resin immobilized Co(II) hybrid catalyst (pages 1416–1426)

      Zhong Xi Huang, Yong Ming Zhang, Hong Li, Ying Hao Luan and Yan Gang Liu

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22481

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      A new immobilized ATRP catalyst, ion exchange resin immobilized cobalt (II), was prepared by the simple method of ion exchange. The immobilized cobalt (II) catalyst had high catalytic activity for the polymerization of MMA. Using the immobilized cobalt (II) catalyst with a small amount of additional soluble CuCl2/Me6TREN, the polymerization was well-controlled. Because the immobilized cobalt (II) catalyst could be easily removed by centrifugation and the amount of the additional soluble CuCl2/Me6TREN was at ppm level (w0(Cu)/w0(MMA)), relatively clean polymers ([Cu] = 8–91 ppm, [Co] = 2–10 ppm) were obtained. The immobilized cobalt (II) catalyst could be reused several times with no obvious decrease of catalytic activity. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    24. Thermally latent polyaddition and curing of Di- and tri-functional hemiacetal esters with diepoxide by salen-zinc complex with tunable catalytic activity and model and networking reactions (pages 1427–1439)

      Hiroyuki Komatsu, Bungo Ochiai and Takeshi Endo

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22482

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      Salen-zinc complexes (Zn/1R) thermal-latently catalyzed the polyaddition of a diepoxide with di- and trifunctional hemiacetal esters, which proceeded at moderate temperatures (100–150 °C) for curing of mixtures containing monomers and initiators. The catalytic activities of Zn/1R depended on the Lewis acidities of the complexes controlled by the electronic character of the salen ligands. The polyadditions with all the salen-zinc complexes proceeded quantitatively at 150 °C, and the use of a trifunctional hemiacetal ester with a diepoxide afforded the corresponding networked polymer.

    25. Polysaccharide-templated twisted assemble of 2-anilinonaphthalene-6-sulfonic acid (pages 1440–1448)

      Naohiko Shimada, Tadashi Okobira, Yoichi Takeda, Seiji Shinkai and Kazuo Sakurai

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22483

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      A natural β-1,3-glucan Schizophyllan (SPG) can form a complex with some hydrophobic molecules. When 2-anilinonaphthalene-6-sulfonic acid (2,6-ANS) was added to SPG, enhanced fluorescence intensity, red-shifted UV absorption spectra, and CD signal were observed. In contrast, any spectral changes were not observed in the addition of N-methyl-2-anilino-6-naphthalensulfonic acid. These results indicate that aromatic amino proton plays an important role for binding to SPG. Furthermore, the CD measurement suggests that 2,6-ANSs arrange in twisted manner in the complex. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    26. Branched polymer via free radical polymerization of chain transfer monomer: A theoretical and experimental investigation (pages 1449–1459)

      Jianhua Liu, Yusong Wang, Qi Fu, Xiangyang Zhu and Wenfang Shi

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22484

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      Above scheme is a schematic illustration for the ideal free radical polymerization of a chain transfer monomer. A simple mathematic model was proposed to describe above process in this article. The architecture of the obtained polymer is determined by the chain transfer constant of a chain transfer monomer according to the proposed model. Homopolymerization of 4-vinyl benzyl thiol as well as its copolymerization with styrene, which was synthesized as a chain transfer monomer, validated the developed model. The conclusions from the model are helpful for selecting appropriate chain transfer monomers to prepare hyper-branched polymers.

    27. Propagation kinetics of free-radical polymerizations in ionic liquids (pages 1460–1469)

      Inga Woecht, Gudrun Schmidt-Naake, Sabine Beuermann, Michael Buback and Nuria García

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22485

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      Pulsed-laser polymerization size-exclusion chromatography (PLP-SEC) experiments of methyl methacrylate (MMA) and glycidyl methacrylate (GMA) in ionic liquids were carried out to determine the propagation rate coefficient, kp. At 40 °C, kp is enhanced by up to a factor of 4 with MMA and by a factor of 2 with GMA. This enhancement of kp primarily results from a lowering of activation energy upon partial replacement of monomer by ionic liquid species.

    28. Fluorescent polymer particles incorporating pyrene derivatives (pages 1470–1475)

      Toshiyuki Tamai, Mitsuru Watanabe, Hajime Maeda and Kazuhiko Mizuno

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22487

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      Fluorescent polymer particles incorporating pyrene and alkynylpyrenes were prepared by miniemulsion polymerization of styrene. The pyrenes were simply dissolved in styrene and then added to the reaction mixture, followed by ultrasonication and the polymerization. The alkynylpyrenes incorporated in the polystyrene particles showed monomer fluorescence emission, of which intensity was same under air and nitrogen. The fluorescence of the alkynylpyrenes in the particles will not be quenched by molecular dioxygen in contrast to that in organic solvents. Incorporation of fluorophore into polymer particles will protect the fluorophore from its undesirable interaction with oxygen, affording the particles highly fluorescent even under air. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    29. Styrene/1,3-butadiene copolymerization by C2-symmetric group 4 metallocenes based catalysts (pages 1476–1487)

      Mariagrazia Napoli, Rosa Ricciardi, Antonia Memoli and Pasquale Longo

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22488

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      Using C2-symmetric group 4 metallocenes based catalysts (rac-[CH2(3-tert-butyl-1-indenyl)2]ZrCl2, rac-[CH2(1-indenyl)2]ZrCl2, and rac-[CH2(3-tert-butyl-1-indenyl)2]TiCl2) we succeeded in obtaining styrene–1,3-butadiene copolymers having styrene homosequences in isotactic arrangement and comonomer distribution almost random or tending to blocky, depending on the used catalyst. The analysis of microstructure of these copolymers revealed that butadiene units in heterosequences are prevailingly 1,4-trans.

    30. Styrene-ethylene co-oligomerization with bis-(diphenylphosphino)-amine/chromium catalysts and the use of the co-oligomerization products in copolymerization reactions with metallocenes (pages 1488–1501)

      Aletta Du Toit, Deon De Wet-Roos, Dawie J. Joubert and Albert J. Van Reenen

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22490

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      Ethylene/styrene co-oligomerization using various bis(diphenylphoshino)amine ligands in combination with chromium is discussed. Subsequent copolymerization of the oligomerization reaction mixture using a metallocene polymerization catalyst result in a copolymer with a branched structure as indicated by Crystaf and 13C NMR analysis. An indication of the ability of the different co-oligomerization products to copolymerize into the polyethylene chain could be established from 13C NMR analysis. Unreacted styrene and the more bulky isomers, 3-phenyl-1-hexene and 3-phenyl-1-octene, are not readily incorporated while branches resulting from the other isomers present in the co-oligomerization reaction mixture are detected in the NMR spectrum.

    31. High-throughput kinetic analysis of acrylate and thiol-ene photopolymerization using temperature and exposure time gradients (pages 1502–1509)

      Peter M. Johnson, Jeffrey W. Stansbury and Christopher N. Bowman

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22491

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      High-throughput workflow used to generate the conversion of a system over multiple temperatures and exposure times. After the gradients are generated, the sample is measured ex situ via Fourier Transform Infrared spectroscopy. The position of this data is then translated into the correct exposure time and temperature value, allowing the data to be shown via a colormap over the entire range of analysis. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    32. Synthesis and properties of highly refractive polyimides derived from fluorene-bridged sulfur-containing dianhydrides and diamines (pages 1510–1520)

      Claudio A. Terraza, Jin-Gang Liu, Yasuhiro Nakamura, Yuji Shibasaki, Shinji Ando and Mitsuru Ueda

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22492

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      A series of fluorene-containing polyimides (PIs) with flexible thioether linkages were designed and synthesized from a newly developed aromatic dianhydride, 4,4′-[(9H-fluorene-9-ylidene)bis(p-phenylsulfanyl)]diphthalic anhydride (FPSP), an aromatic diamine, 9,9′-bis[4-(p-aminophenyl)sulfanylphenyl]fluorene (ASPF), and several other monomers. Refractive indices higher than 1.69, birefringences lower than 0.008, and glass transition temperatures higher than 220 °C were achieved by the synergic effects of the highly aromatic fluorene moiety, flexible thioether linkages, and high molar refractive sulfur groups. In addition, the PI films exhibited good optical transparency in the visible light region with the transmittances higher than 80% at 450 nm.

    33. Synthesis of chalcone-based fluorescent polymers: Diels-Alder reaction of chalcones and their polymerization through ROMP (pages 1521–1531)

      R. Kamakshi and B. S. R. Reddy

      Version of Record online: 28 DEC 2007 | DOI: 10.1002/pola.22493

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      ROMP of Diels-Alder adducts from chalcones and CPD was carried out using Grubb's catalyst. The polymers were found to have good fluorescent properties.

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