Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 45 Issue 15

1 August 2007

Volume 45, Issue 15

Pages 3135–3500

  1. Articles

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Notes
    1. Short chain branching profiles in polyethylene from the Phillips Cr/silica catalyst (pages 3135–3149)

      Paul J. DesLauriers and Max P. McDaniel

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22174

      Thumbnail image of graphical abstract

      The 3D surface below shows the placement of branches in polyethylene copolymers as a function of molecular weight. The Phillips Cr/silica catalyst tends to concentrate comonomer into the low molecular weight part of the distribution (the small island in the graph). However, the extent to which this happens can be influenced considerably by catalyst and reactor variables.

    2. Renewable chain transfer agents for metallocene polymerizations: The effects of chiral monoterpenes on the polyolefin molecular weight and isotacticity (pages 3150–3165)

      Robert T. Mathers and Krishnan Damodaran

      Version of Record online: 6 JUN 2007 | DOI: 10.1002/pola.22111

      Thumbnail image of graphical abstract

      Monoterpenes are renewable chain transfer agents for metallocene catalysts. The polymerization of ethylene, propylene, and 1-hexene has been examined in d-limonene, α-pinene, and hydrogenated d-limonene. The chain transfer to d-limonene was detected by 1H NMR and size exclusion chromatography. The effect of chiral polymerization solvents on the microstructure of isotactic poly(1-hexene) and isotactic polypropylene was examined by DSC and 13C NMR.

    3. Linear and branched fluoroazo-benzene chromophores with increased compatibility in semifluorinated polymers (pages 3166–3177)

      Victoria E. Campbell, Peerasak Paoprasert, Justin D. Mykietyn, Insik In, David J. McGee and Padma Gopalan

      Version of Record online: 6 JUN 2007 | DOI: 10.1002/pola.22145

      Thumbnail image of graphical abstract

      A family of fluorinated azobenzene-based push-pull chromophores with one, two and three trifluorovinyl ether groups in linear and branched architecture was synthesized and utilized as active materials in the low optical loss electro-optic composites. The fluorinated azobenzene chromophores exhibited increased solubility (30 ∼ 50 wt.-%) in semifluorinated polymer host such as perfluorocylobutane (PFCB) aromatic ether resin after crosslinking, compared with the commercially available non-fluorinated azobenzene chromophore Disperse Red 1 (1 ∼ 2 wt.-%). The resulting fluorinated EO composites showed excellent optical clarity, low birefringence and low optical loss less than 0.5 dB/cm at 1550 nm.

    4. Investigation into the ROMP copolymerization of peptide- and PEG-functionalized norbornene derivatives (pages 3178–3190)

      Stefano C. G. Biagini and Alison L. Parry

      Version of Record online: 6 JUN 2007 | DOI: 10.1002/pola.22068

      Thumbnail image of graphical abstract

      Water compatible polymers from the ROMP copolymerization of peptide- and PEG-functionalised norbornene derivatives, using RuCl2(PCy3)2CHPh.

    5. Copolymerization of sec-butenyl acetate with styrene via emulsion polymerization (pages 3191–3203)

      Alp H. Alidedeoglu, Sandipan Dutta, Rahul Misra, James W. Rawlins and Sarah E. Morgan

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22069

      Thumbnail image of graphical abstract

      The allylic monomer, sec-butenyl acetate (SBA) was copolymerized with styrene via a semicontinuous emulsion polymerization. The resulting copolymers yielded high conversions with substantial SBA incorporation. A high degree of degradative chain transfer was observed, evidenced by decreases in molecular weight and monomer conversion. A single glass transition temperature (Tg) and unimodal particle size distributions were obtained. These results indicate the potential utility of SBA, as an effective chain transfer agent, to control molecular weight of styrene polymers while providing high conversions, Tg modification, and enhanced film formation properties.

    6. Sugars-grafted aliphatic biodegradable poly(L-lactide-co-carbonate)s by click reaction and their specific interaction with lectin molecules (pages 3204–3217)

      Changhai Lu, Quan Shi, Xuesi Chen, Tiancheng Lu, Zhigang Xie, Xiuli Hu, Jia Ma and Xiabin Jing

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22070

      Thumbnail image of graphical abstract

      A novel biodegradable aliphatic poly(L-lactide-co-carbonate) bearing pendant sugar moieties, such as glucose or lactose, was prepared by the typical “click reaction,” that is, Cu(I)-catalyzed cycloaddition of azide and alkyne. This reaction provides a simple and highly efficient approach to biofunctionalization of synthetic polymers. The resultant sugar-grafted copolymer films show lower cytotoxicity against L929 cells and improved specific binding ability with lectins (Con A and RCA) molecules than its precursor.

    7. RGD peptide grafted biodegradable amphiphilic triblock copolymer poly(glutamic acid)-b-poly(L-lactide)-b-poly(glutamic acid): Synthesis and self-assembly (pages 3218–3230)

      Chao Deng, Xuesi Chen, Jing Sun, Tiancheng Lu, Wenshou Wang and Xiabin Jing

      Version of Record online: 6 JUN 2007 | DOI: 10.1002/pola.22071

      Thumbnail image of graphical abstract

      A novel amphiphilic biodegradable triblock copolymer (PGL-PLA-PGL) with polylactide (PLA) as hydrophobic block and poly(glutamic acid) (PGL) as hydrophilic blocks was successfully synthesized by ring-opening polymerization of L-lactide and N-carboxyanhydride of glutamic acid consecutively and by subsequent catalytic hydrogenation. The pendant carboxyl groups of the triblock copolymer were further combined with a cell-adhesive peptide GRGDSY to obtain a GRGDSY-grafted product. PGL-PLA-PGL and its grafted derivative exhibited improved cell adhesion and spreading ability compared with pure PLA, and they self-assembled in aqueous solution into micelles of spindly shape and spherical shape, respectively.

    8. Blood compatibility of fluorodiol-containing polyurethanes (pages 3231–3242)

      Y. H. Lin, N. K. Chou, C. H. Chang, S. S. Wang, S. H. Chu and K. H. Hsieh

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22072

      Thumbnail image of graphical abstract

      We synthesized novel fluorodiol-containing polyurethanes possessing polytetramethyl oxide and 1H,1H,12H,12H-perfluoro-1,12-dodecanediol groups. These structures can exhibit microphase separation, which induces a low degree of platelet adhesion. In addition, a higher content of fluorine atoms exposed on the surface results in a lower surface energy, a lower relative index of platelet adhesion, and a lower fibrinogen/albumin adsorption ratio.

    9. Synthesis and characterization of light-emitting main-chain metallo-polymers containing bis-terpyridyl ligands with various lateral substituents (pages 3243–3255)

      Yi-Yu Chen and Hong-Cheu Lin

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22073

      Thumbnail image of graphical abstract

      A series of conjugated monomers (5a-5d) with various lateral substituents were symmetrically synthesized by the Sonogashira coupling reaction. These monomers were further reacted with zinc(II) ions and subsequently anion exchanged by self-assembly process to produce metallo-supramolecular polymers (6a-6d). PLEDs employing these polymers as emitters gave yellow to orange electroluminescence emissions with turn-on voltages around 6 V. The maximum power efficiency, external quantum yield, and brightness of the PLED device containing polymer 6c were 0.33 cd A−1 (at 14 V), 1.02%, and 931 cd m−2 (at 14 V), respectively.

    10. Core-shell microspheres with surface grafted poly(vinyl alcohol) as drug carriers for the treatment of hepatocellular carcinoma (pages 3256–3272)

      T. L. Uyen Nguyen, Brooke Farrugia, Thomas P. Davis, Christopher Barner-Kowollik and Martina H. Stenzel

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22074

      Thumbnail image of graphical abstract

      Poly(vinyl alcohol) coated microspheres were obtained by surface grafting of vinylpivalate onto beads using residual double bonds. Two techniques—free radical polymerization and the macromolecular design via the interchange of xanthates (MADIX) process—were utilized and their outcome was compared. The resulting core-shell beads with particle sizes of around 40 μm were hydrolyzed. As a result, the microspheres were suspendable in aqueous conditions. After drug loading with clofazimine the particles were tested towards their suitability as a drug carrier system.

    11. Preparation and properties of polyethoxysilsesquioxane-C60 hybrids (pages 3273–3279)

      Takahiro Gunji, Yosuke Sakai, Koji Arimitsu and Yoshimoto Abe

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22076

      Thumbnail image of graphical abstract

      Free-standing films of C60-polyethoxysiloxane hybrids were prepared, and their optical limiting properties were evaluated. C60-polyethoxysiloxanes were prepared by a co-hydrolytic polycondensation of triethoxysilylated C60 with tetraethoxysilane. Transparent and flexible free-standing films were prepared by aging an ethanol solution of C60-polyethoxysiloxane, which showed an optical limiting property.

    12. One- and two-photon activity of cross-conjugated photoinitiators with bathochromic shift (pages 3280–3291)

      Christian Heller, Niklas Pucher, Bernhard Seidl, Kadiriye Kalinyaprak-Icten, Gerald Ullrich, Ladislav Kuna, Valentin Satzinger, Volker Schmidt, Helga C. Lichtenegger, Jürgen Stampfl and Robert Liska

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22078

      Thumbnail image of graphical abstract

      In these investigations we prepared and investigated several initiators for radical photopolymerization based on 1,5-diphenylpenta-1,4-diyn-3-one with different donor substituents. UV-Vis spectroscopy revealed a gradual red-shift of λmax and higher extinction in the order of the donor capability. The photoinitiator activity for classical single photon absorption was determined by photo-DSC experiments. Because of the D-π-A-π-D system of these compounds two-photon induced 3D photopolymerization experiments were performed. Some of the new initiators gave outstanding performance compared to often applied single photon initiators.

    13. 4-methoxy-substituted poly(triphenylamine): A p-type polymer with highly photoluminescent and reversible oxidative electrochromic characteristics (pages 3292–3302)

      Guey-Sheng Liou, Yi-Lung Yang, Wen-Chang Chen and Yuhlong Oliver Su

      Version of Record online: 11 JUN 2007 | DOI: 10.1002/pola.22079

      Thumbnail image of graphical abstract

      A 4-methoxy-substituted triphenylamine-containing homopolymer, poly[N,N-diphenyl-4-methoxyphenylamine-4′,4″-diyl] (PMeOTPA), with blue light (435 nm) fluorescence quantum efficiency up to 79 % was easily prepared by oxidative coupling polymerization. It exhibited good thermal stability with 10 % weight-loss temperatures above 500 °C under a nitrogen atmosphere. The simply designed homopolymer revealed moderate stability of electrochromic characteristics, changing color from original pale yellowish to red, and then to black. The PMeOTPA based field effect transistor also showed p-type characteristics with significant temperature dependence. The present study suggests that PMeOTPA is a multifunctional polymer for various optoelectronic device applications. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    14. Synthesis of dendronized polymer brushes containing metallo-supramolecular polymer side chains (pages 3303–3310)

      Yanhong Zhang, Zizhen Xu, Xiaokai Li and Yongming Chen

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22080

      Thumbnail image of graphical abstract

      Dendronized copolymers were further grafted uniformly with PEO chains through metallo-supramolecular interaction and a series of worm-like polymers of amphiphilic nature were prepared. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    15. Nanostructured polymetallaynes of controlled length: Synthesis and characterization of oligomers and polymers from 1,1′-bis-(ethynyl)4,4′-biphenyl bridging Pt(II) or Pd(II) centers (pages 3311–3329)

      Ilaria Fratoddi, Chiara Battocchio, Alessandra L. Groia and Maria V. Russo

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22081

      Thumbnail image of graphical abstract

      The reactivity of trans or cis-[dichlorobis(tributylphosphine)platinum(II)] and trans-[dichlorobis(tributylphosphine)palladium(II)] with 1,1′-bis-(ethynyl)4,4′-biphenyl, DEBP, was investigated by a systematic variation of the reaction conditions. The formation of polymers and oligomers with defined chain length [[BOND]M(PBu3)2(C[TRIPLE BOND]C[BOND]C6H4[BOND]C6H4[BOND]C[TRIPLE BOND] C[BOND])]n was achieved. A series of model reactions monitored by XPS, GPC, and NMR 31P spectroscopy showed the route to modulate the chain growth. Polymetallaynes with nanostructured morphology could be obtained by a simple casting procedure for the polymer deposition.

    16. Divergent synthesis of dendrimer-like macromolecules through a combination of atom transfer radical polymerization and click reaction (pages 3330–3341)

      Qingchun Liu, Peng Zhao and Yongming Chen

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22082

      Thumbnail image of graphical abstract

      Dendrimer-like PS of the second and third generations was prepared by the combination of ATRP and click reaction. The growth of each generation involved two steps of terminal group modification reactions and a step of chain propagation. When the second generation of dendrimer-like PS served as the macroinitiator of the ATRP of tBA, the dendrimer-like block copolymer with a PS shell and a PtBA corona were also synthesized.

    17. Synthesis and characterization of 4-arm star side-chain liquid crystalline polymers containing azobenzene with different terminal substituents via ATRP (pages 3342–3348)

      Xinde Tang, Longcheng Gao, Nianfeng Han, Xinghe Fan and Qifeng Zhou

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22084

      Thumbnail image of graphical abstract

      4-Arm star side-chain liquid crystalline (LC) polymers containing azobenzene with different terminal substituents were synthesized by atom transfer radical polymerization (ATRP). Tetrafunctional initiator prepared by the esterification between pentaerythritol and 2-bromoisobutyryl bromide was utilized to initiate the polymerization of 6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate (MMAzo) and 6-[4-(4-ethoxyphenylazo)phenoxy]hexyl methacrylate (EMAzo), respectively. The 4-arm star side-chain LC polymer with p-methoxyazobenzene moieties exhibits a smectic and a nematic phase, while that with p-ethoxyazobenzene moieties shows only a nematic phase, which derives of different terminal substituents. The star polymers have similar LC behavior to the corresponding linear homopolymers, whereas transition temperatures decrease slightly. Both star polymers show photoresponsive isomerization under the irradiation with UV–vis light.

    18. Preparation and morphological, electrical, and mechanical properties of polyimide-grafted MWCNT/polyimide composite (pages 3349–3358)

      Siu-Ming Yuen, Chen-Chi M. Ma, Chin-Lung Chiang, Yao-Yu Lin and Chih-Chun Teng

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22085

      Thumbnail image of graphical abstract

      Acid-modified carbon nanotube (MWCNT) was grafted with soluble polyimide, which was prepared by reacting 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with 4,4′-diphenylmethane diisocyanate (MDI). Then was added to the polyamic acid, which was prepared by reacting 4,4′-oxydianiline (ODA) and 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA), and heated to 300 °C to form polyimide/carbon nanotube composite via imidation. TEM microphotographs show the diameter of soluble polyimide grafted MWCNT was increased. PI-g-MWCNT was well dispersed in the polymer matrix. Electrical resistivity, percolation threshold and tensile properties of MWCNT/polyimide composites have been investigated.

    19. Morphology of PU/PMMA hybrid particles from miniemulsion polymerization: Thermodynamic considerations (pages 3359–3369)

      Chien-Yu Li, Wen-Yen Chiu and Trong-Ming Don

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22086

      Thumbnail image of graphical abstract

      By thermodynamic consideration, the Gibbs free energy changes of PU/PMMA hybrid particles prepared from miniemulsion polymerization were calculated and related to the morphology.

    20. Model reaction for thermally latent curing through addition of hemiacetal ester and epoxide by schiff-base–zinc halide complexes (pages 3370–3379)

      Hiroyuki Komatsu, Bungo Ochiai, Tetsuo Hino and Takeshi Endo

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22087

      Thumbnail image of graphical abstract

      Schiff-base—zinc halide complexes (ZnX2/1) thermal-latently catalyze the addition of glycidyl phenyl ether (2) and 1-propoxyethyl-2-ethylhexanoate (3) only at moderately elevated temperatures, while the mixture of 2, 3, and ZnX2/1 can be stored for several months under ambient conditions keeping the reactivity at elevated temperatures. It demonstrates that the present system is potentially applicable for efficient curing.

    21. White electroluminescence from a single polyfluorene containing bis-DCM units (pages 3380–3390)

      Sang Kyu Lee, Byung-Jun Jung, Taek Ahn, Young Kwan Jung, Jeong-Ik Lee, In-Nam Kang, Jonghee Lee, Jong-Hwa Park and Hong Ku Shim

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22090

      Thumbnail image of graphical abstract

      The EL device based on the single polyfluorene chain containing bis-DCM units exhibited a pure white light emission with CIE coordinates of (0.33, 0.31) and a quite stable white-light emission at different driving voltages.

    22. Pd (II)-catalyzed vinyl addition polymerization of novel functionalized norbornene bearing dimethyl carboxylate groups (pages 3391–3399)

      Binyuan Liu, Yang Li, Boo-Gyo Shin, Do Yeung Yoon, IL Kim, Li Zhang and Weidong Yan

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22091

      Thumbnail image of graphical abstract

      Three novel functionalized PNB-2,3-dimethyl carboxylates (carboxylates—acetate, propionate, butyrate) are synthesized as a vinyl-type with a palladium (II) catalyst in high yield. The resulting PNB-dimethyl carboxylates show good solubility in common organic and high thermal stability up to 360 °C. The glass translation temperature was determined by DMA at 331, 324, and 318 °C for PNB-dimethyl acetate, PNB-dimethyl propionate, and PNB-dimethyl, respectively.

    23. Crosslinkable polyurethane bearing a methacrylate structure in the side chain (pages 3400–3407)

      Bungo Ochiai, Shin-Ich Sato and Takeshi Endo

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22092

      Thumbnail image of graphical abstract

      Polyurethanes having methacrylate side chains were prepared by the urethanization of poly(hydroxyurethane) with 2-methacrylorloxyethyl isocyanate. The urethanization under mild conditions afforded a soluble polyurethane with methacrylate structures quantitatively in the side chains, whereas that at a higher temperature afforded a crosslinked product. The soluble polymer was thermally curable and served as a precursor for crosslinked polymers. The thermal behaviors and solvent absorbency of the crosslinked polymers suggested the flexibility of the crosslinked polymers.

    24. Synthesis and properties of polyurethanes bearing urethane moieties in the side chain (pages 3408–3414)

      Bungo Ochiai, Shin-Ich Sato and Takeshi Endo

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22093

      Thumbnail image of graphical abstract

      Polyurethanes having urethane side chains were prepared by the urethanization of hydroxyl groups in poly(hydroxyurethane) with isocyanates. Differential scanning calorimetry analysis of the resulting polymers suggested that the urethane groups in the side chain formed intermolecular hydrogen bonds. A polyurethane bearing triethoxysilyl carbamoyl side chains could also be prepared through the reaction of poly(hydroxyurethane) and 3-triethoxysilylpropyl isocyanate.

    25. Highly active ethylene polymerization and copolymerization with norbornene using bis(imino-indolide) titanium dichloride–MAO system (pages 3415–3430)

      Weiwei Zuo, Wen-Hua Sun, Shu Zhang, Peng Hao and Akinobu Shiga

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22094

      Thumbnail image of graphical abstract

      A series of titanium complexes bearing N-((3-chloro-1H-indol-2-yl)methylene)benzenamines were synthesized, and the X-ray diffraction analyses revealed six-coordinated distorted octahedral geometry around the titanium centers with a pair of cis-oriented chlorides. When activated by MAO, the complexes performed high activity toward ethylene homopolymerization and ethylene/norbornene copolymerization. Improved catalytic activities were observed at higher reaction temperatures and the active species remained stable at the elevated temperatures, which could be useful for industrious consideration. In addition, under optimum conditions, this system has produced ultra-high-molecular-weight polyethylenes at remarkable polymerization rate. A “comonomer effect” was observed for copolymerization of ethylene and norbornene under certain conditions.

    26. A novel and facile preparation method of hollow silica spheres containing small SiO2 cores (pages 3431–3439)

      Xinjian Cheng, Min Chen, Limin Wu and Bo You

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22095

      Thumbnail image of graphical abstract

      This article provided a very simple route to fabricate hollow silica spheres with loading small silica particles inside. In this approach, positively charged SiO2/polystyrene core-shell particles were synthesized first. When Silica shells formed on the surfaces of the particles, the polystyrene was dissolved subsequently even synchronously in the same medium to directly form hollow silica spheres with small silica particles cores.

    27. Synthesis and opto-electrical properties of dendron-containing poly(2,3-diphenyl-1,4-phenylenevinylene) derivatives (pages 3440–3450)

      Sheng-Hsiung Yang, Shiang-Ying Chen, Yu-Chun Wu and Chain-Shu Hsu

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22207

      Thumbnail image of graphical abstract

      Novel poly(2,3-diphenyl-1,4-phenylene vinylene) derivatives containing dendritic side groups were synthesized. The photoluminescence quantum efficiency is significantly enhanced with increasing the generation of dendrons. The electrochemical analysis revealed that hole-injection is also improved by increasing dendritic generation.

    28. Preparation of polymer-grafted carbon black nanoparticles by surface-initiated atom transfer radical polymerization (pages 3451–3459)

      Qiang Yang, Li Wang, Wei-dong Xiang, Jun-feng Zhou and Qiao-hua Tan

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22077

      Thumbnail image of graphical abstract

      ATRP initiator was introduced onto carbon black surface via a new synthesis route. Pristine carbon black was first oxidized with nitric acid to produce carboxylic groups. Then, the oxidized carbon black was successively reacted with thionyl chloride and glycol to introduce hydroxyl groups. Finally, hydroxyl group on carbon black surface was reacted with 2-bromo-2-methylpropionyl bromide to introduce ATRP initiator.

    29. Preparation of side-on bisazobenzene-containing homopolymers and block copolymers via ATRP and studies on their photoisomerization and photoalignment behaviors (pages 3460–3472)

      Ming Jin, Ran Lu, Qing Xin Yang, Chun Yan Bao, Ren Sheng, Ting Hua Xu and YingYing Zhao

      Version of Record online: 15 JUN 2007 | DOI: 10.1002/pola.22088

      Thumbnail image of graphical abstract

      In this article, a set of side-on bisazobenzene-containing homopolymers without polystyrene and copolymers with polystyrene were prepared by ATRP. The studies of UV–vis spectra and photoinduced birefringence of the films of these polymers showed that the bisazobenzene chromophores located at side chains of the polymers have fast photoisomerization properties and good photoalignment behaviors under irradiation of linear 488 Ar+ laser.

  2. Rapid Communications

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Notes
    1. You have free access to this content
      Synthesis and properties of a novel hyperbranched borate (pages 3473–3476)

      Yuhong Liu, Jipeng Qiang and Xinli Jing

      Version of Record online: 19 JUN 2007 | DOI: 10.1002/pola.22089

      Thumbnail image of graphical abstract

      A novel hyperbranched polymer with aryl borate backbone was obtained by a facile A2+B3 method. Thermal analysis revealed that HBb exhibited excellent thermal stability with a Tg of 221 °C and a weight residue of 71.3% at 800 °C under nitrogen atmosphere. HBb displayed good solubility with readily soluble in common polar solvents. By blending 10 wt % HBb with phenolic resins, the weight residue of the cured thermoset resins was greatly improved.

    2. You have free access to this content
      Preparation of poly(acrylamide)/MWNTs nanocomposite using carboxylated MWNTs (pages 3477–3481)

      Jinho Hong, Chang Kook Hong, Soonja Choe and Sang Eun Shim

      Version of Record online: 19 JUN 2007 | DOI: 10.1002/pola.22122

      Thumbnail image of graphical abstract

      Polyacrylamide/MWNTs nanocomposite is prepared using MWNTs functionalized with carboxylic acid or carboxylic anion groups. The modified MWNTs show significantly improved colloidal stability without aggregation in aqueous acrylamide solution. The solution was in-situ polymerized to give a well-dispersed PAAm/MWNTs nanocomposite.

    3. You have free access to this content
      Ambient temperature synthesis of well-defined microspheres via precipitation polymerization initiated by UV-irradiation (pages 3482–3487)

      Raymond Joso, Eh Hau Pan, Martina H. Stenzel, Thomas P. Davis, Christopher Barner-Kowollik and Leonie Barner

      Version of Record online: 19 JUN 2007 | DOI: 10.1002/pola.22132

      Thumbnail image of graphical abstract

      Ambient temperature UV initiated precipitation polymerization is demonstrated to be an efficient avenue to well-defined microspheres. It is demonstrated that the microsphere size can be tailored by the choice and concentration of photo initiator as well as reaction temperature. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    4. You have free access to this content
      Efficient metal-free coupling of polystyrene chains using silane radical atom abstraction (pages 3488–3493)

      Sona Thakur and Eric S. Tillman

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/pola.22141

      Thumbnail image of graphical abstract

      Silane radicals were used to abstract bromine from the chain terminus of monobrominated polystyrene (PStBr) chains, generating PS radicals which underwent coupling reactions to produce polystyrene (PS) of controlled, predictable molecular weights and low polydispersity index (PDI) values. This method, introduced as silane radical atom abstraction (SRAA), foregoes the requirement of metal catalysts that are utilized in atom transfer radical coupling (ATRC), while giving comparable results.

  3. Notes

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Notes
    1. You have free access to this content
      Ruthenium quinoline and quinoxaline complexes: Thermally triggered initiators for ring opening metathesis polymerization (pages 3494–3500)

      Xaver Gstrein, Daniel Burtscher, Anna Szadkowska, Michał Barbasiewicz, Franz Stelzer, Karol Grela and Christian Slugovc

      Version of Record online: 19 JUN 2007 | DOI: 10.1002/pola.22083

      Thumbnail image of graphical abstract

      Olefin metathesis catalysts bearing chelating carbene ligands based on 8-vinylquinoline and 5-vinylquinoxaline were examined as initiators for Ring Opening Metathesis Polymerization. Model-polymerizations with these initiators were studied by differential scanning calorimetry and nuclear magnetic resonance. Results revealed a pronounced latency at room temperature and high activity at elevated temperatures. Combined solutions of the initiators and the monomers can even be stored for two weeks at room temperature. While no concomitant polymerization occurred during this time, polymerization of the mixtures took place upon heating.

SEARCH

SEARCH BY CITATION