Journal of Polymer Science Part A: Polymer Chemistry

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

15 September 2002

Volume 40, Issue 18

Pages 3093–3189

  1. Articles

    1. Top of page
    2. Articles
    1. Novel tricomponent membranes containing poly(ethylene glycol)/poly(pentamethylcyclopentasiloxane)/poly(dimethylsiloxane) domains (pages 3093–3102)

      Pious Kurian and Joseph P. Kennedy

      Article first published online: 26 JUL 2002 | DOI: 10.1002/pola.10391

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      Novel tricomponent networks consisting of well-defined poly(ethylene glycol) and polydimethylsiloxane strands crosslinked/reinforced by polypentamethylcyclopentasiloxane domains have been synthesized and characterized. Three thermal transitions indicate a phase-separated tricomponent nanostructure. The syntheses of networks with sufficient mechanical properties (tensile strength: 2–5 MPa, elongation: 100–800%) for various applications have been demonstrated.

    2. Application of ketenes to well-defined polyester synthesis (4): End-capping reactions in living anionic polymerization of ethylphenylketene (pages 3103–3111)

      Atsushi Sudo and Takeshi Endo

      Article first published online: 29 JUL 2002 | DOI: 10.1002/pola.10393

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      By living anionic polymerization of ethylphenylketene (EPK) using lithium alkoxide as an initiator, a polyester having a lithium enolate at the terminal was prepared. Subsequent treatment of the corresponding macroanion with electrophiles such as alkyl halide and acyl halide successfully afforded the end-capped polyester having a narrow molecular weight distribution.

    3. Novel spherical Ziegler–Natta catalyst for polymerization and copolymerization. I. Spherical MgCl2 support (pages 3112–3119)

      Zhao-Yang Ye, Li Wang, Lian-Fang Feng, Xue-Ping Gu, Hai-Hua Chen, Pu-Yu Zhang, Jie Pan, Shan Jiang and Lin-Xian Feng

      Article first published online: 26 JUL 2002 | DOI: 10.1002/pola.10398

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      Spherical MgCl2 adducts used as supports for a Ziegler–Natta catalyst for olefin polymerization were prepared by the general simple precipitation method. It is well known that active species supported on spherical MgCl2 adducts have made great progress in controlling polymer morphology as spherical particles. Spherical adducts were made under various conditions, and detailed investigations were made into the influence of MgCl2/EtOH (mol/mol) and the dispersion speeds on the particle size and particle size distribution. Moreover, the influence of ethanol on the crystal structure of MgCl2 was further examined, being considered the key point in the preparation of suitable supports for the latest generation Ziegler–Natta catalyst.

    4. Synthesis of fluorosilicone having highly fluorinated alkyl side chains based on the hydrosilylation of fluorinated olefins with polyhydromethylsiloxane (pages 3120–3128)

      Y. Furukawa and M. Kotera

      Article first published online: 1 AUG 2002 | DOI: 10.1002/pola.10396

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      The hydrosilylation of fluorinated olefins with polyhydromethylsiloxane (PHMS) in the presence of a platinum catalyst was investigated to synthesize fluorosilicone having highly fluorinated alkyl side chains. The presence or the absence and the kind of a connecting group between the Rf group and a vinyl group affected the hydrosilylation of fluorinated olefins with PHMS.

    5. Synthesis of biodegradable copolymers with low-toxicity zirconium compounds. III. Synthesis and chain-microstructure analysis of terpolymer obtained from L-lactide, glycolide, and ϵ-caprolactone initiated by zirconium(IV) acetylacetonate (pages 3129–3143)

      Piotr Dobrzynski

      Article first published online: 1 AUG 2002 | DOI: 10.1002/pola.10401

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      This article strives to show a new method of terpolymerization of glycolide with lactide and ϵ-caprolactone using low-toxicity zirconium(IV) acetylacetonate [Zr(acac)4] as an initiator. The microstructure of the obtained terpolymer was determined by NMR spectroscopy and then compared with terpolymers obtained in the presence of stannous(II) octoate. Samples obtained with Zr(acac)4 were characterized by a segmental-chain microstructure. Such a structure is formed as a result of strong transesterification caused by active caproyl chain endings attacking the glycolidyl groups. Domination of this type of transesterification is shown.

    6. Synthesis and properties of crosslinked polyvinylformamide and polyvinylamine hydrogels in conjunction with silica particles (pages 3144–3152)

      Torsten Meyer, Thomas Hellweg, Stefan Spange, Stephanie Hesse, Christian Jäger and Cornelia Bellmann

      Article first published online: 30 JUL 2002 | DOI: 10.1002/pola.10400

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      Polyvinylamine hydrogels with silica particles encapsulated (PVAm/silica) were produced by a two-step synthesis from vinylformamide (VFA) and 1,3-divinylimidazolidin-2-one (1,3-bisvinylethyleneurea, BVU), as the crosslinker, by radical copolymerization in silica/water suspensions using different compositions of VFA/BVU. The target product PVAm/silica was obtained by acidic hydrolysis of the PVFA/silica hydrogels in a second step. The swelling capacity of the two systems was characterized by the correlation length ξ (or hydrodynamic blob size) of the network meshes with small-angle neutron scattering experiments. ξ is significantly larger for PVAm/silica than for PVFA/silica, which corresponds to the observed higher swelling capacity of this polyelectrolyte material.

    7. Atom transfer radical polymerization of styrene in toluene/water mixtures (pages 3153–3160)

      Traian Sarbu, Tomislav Pintauer, Blayne McKenzie and Krzysztof Matyjaszewski

      Article first published online: 6 AUG 2002 | DOI: 10.1002/pola.10404

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      The atom transfer radical polymerization (ATRP) of styrene in water/toluene mixtures was studied. The partitioning of copper halides resulted in almost complete migration of CuII into the aqueous phase, which assisted with catalyst removal after polymerization. For example, the amount of residual copper determined by inductively coupled plasma was less than 1 ppm when the polymerization mixture was exposed to air with stirring for 30 min.

    8. Self-assembling directed synthesis of a novel terephthalamide-bridged ladderlike polysiloxane (pages 3161–3170)

      Hui Li, Chunqing Liu, Guangqing Guo, Xiaoshu Zhou, Jianmin Zhang, Deyan Shen, Zhongxing Zhang, Ping Xie, Shuyan Yu and Rongben Zhang

      Article first published online: 6 AUG 2002 | DOI: 10.1002/pola.10403

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      A novel, soluble terephthalamide-bridged ladderlike polysiloxane (L) was synthesized successfully for the first time by stepwise coupling polymerization. The process involved the hydrogen-bonding self-assembly of amido groups, which resulted in the formation of a more highly ordered polymeric structure.

    9. Use of α-diketones as visible photoinitiators for the photocrosslinking of waterborne latex paints (pages 3171–3181)

      C. Bibaut-Renauld, D. Burget, J. P. Fouassier, C. G. Varelas, J. Thomatos, G. Tsagaropoulos, L. O. Ryrfors and O. J. Karlsson

      Article first published online: 6 AUG 2002 | DOI: 10.1002/pola.10407

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      α-Diketones were used as visible photoinitiators for the crosslinking of waterborne latex dispersions in the presence of acrylic monomers. Camphorquinone allows a fast curing of the acrylic waterborne coating in air. The properties of the sunlight-cured volatile organic compound (VOC)-free pigmented paints prepared from the waterborne latex are better than the equivalent conventional paint containing VOCs.

    10. Novel synthesis of cyclic methylvinylsiloxanes by the reaction of methylvinyl diethoxysilane with phosphorous pentachloride (pages 3182–3189)

      Andrés Ciolino, Bruno M. Vuano, Olga Pieroni, Marcelo A. Villar and Enrique M. Vallés

      Article first published online: 6 AUG 2002 | DOI: 10.1002/pola.10406

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      A novel synthesis of the cyclic oligomers [(H2C[DOUBLE BOND]CH)(CH3)SiO]n obtained by the reaction between phosphorous pentachloride and methylvinyl diethoxysilane is reported. According to gas chromatography/mass spectrometry data, the reaction product consisted of a mixture of cyclic oligomers in which the most important fractions were composed of cycles with n = 5, 6, or 7. The reaction product was also characterized by Fourier transform infrared and 1H and 13C NMR spectroscopy.

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