Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 42 Issue 2

15 January 2004

Volume 42, Issue 2

Pages 215–385

  1. Highlight

    1. Top of page
    2. Highlight
    3. Articles
    1. You have free access to this content
      Asymmetric polymerization using C1 resources (pages 215–221)

      Kyoko Nozaki

      Version of Record online: 3 DEC 2003 | DOI: 10.1002/pola.11025

      Thumbnail image of graphical abstract

      Two examples are described of chiral-metal-complex-catalyzed asymmetric alternating copolymerization with C1 resources.

  2. Articles

    1. Top of page
    2. Highlight
    3. Articles
    1. Synthesis and properties of organosoluble polyimides based on 4,4′-bis(4-amino-2-trifluoromethylphenoxy)benzophenone (pages 222–236)

      Chin-Ping Yang and Yu-Yang Su

      Version of Record online: 3 DEC 2003 | DOI: 10.1002/pola.11012

      Thumbnail image of graphical abstract

      A novel, fluorinated diamine monomer with the ether–ketone group, 4,4′-bis(4-amino-2-trifluoromethylphenoxy)benzophenone (2), was prepared from 2-chloro-5-nitrobenzotrifluoride and 4,4′-dihydroxybenzophenone. Flourinated polyimides 5af and copolyimides (co-PIs) 5c/af were synthesized from 2 and various commercial aromatic dianhydrides via thermal or chemical imidization. Polyimides 5af had inherent viscosities ranging from 0.72 to 1.22 dL/g. Besides the chemical imidization of 5c(C), the 5(C) series were soluble in amide-type solvents and even in less polar solvents, but polyimides 5af prepared via thermal imidization were insoluble. In comparison of the polyimide 5 series with the analogous non-fluorinated polyimides 6 series based on 4,4′-bis(4-aminophenoxy)benzophenone, the 5 series revealed better solubility, lower color intensity, dielectric constant, and moisture absorption.

    2. Mechanism of the anionic polymerization of methyl methacrylate initiated by tetramethylammonium–triphenylmethide in tetrahydrofuran (pages 237–244)

      William N. Warner, Jinbo Hu, G. K. Surya Prakash, George A. Olah and Thieo E. Hogen-Esch

      Version of Record online: 3 DEC 2003 | DOI: 10.1002/pola.11019

      Thumbnail image of graphical abstract

      A tetramethylammonium–triphenylmethide initiator generated in situ by the reaction of triphenylmethyltrimethylsilane with tetramethylammonium fluoride in tetrahydrofuran polymerized methyl methacrylate in tetrahydrofuran at −78 °C in quantitative yields with polydispersities of less than 1.1. Although the initiator efficiencies were low (9–40%) because of relatively slow initiation on the polymerization timescale, the initiation appeared to be rapid enough to give relatively narrow molecular weight distributions.

    3. Chain-growth limiting reactions in the cationic polymerization of 3-ethyl-3-hydroxymethyloxetane (pages 245–252)

      Melania Bednarek and Przemysław Kubisa

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.11002

      Thumbnail image of graphical abstract

      Cationic polymerization of 3-ethyl-3-hydroxymethyloxetane leads to cyclic polymers with limited molecular weights due to back-biting. It has been shown that intramolecular chain transfer to polymer (back-biting) proceeds as an attack of an hydroxy group (and not an ether group from the chain) on the growing chain end.

    4. Ultraviolet grafting of methacrylic acid and acrylic acid on high-density polyethylene in different solvents and the wettability of grafted high-density polyethylene. I. Grafting (pages 253–262)

      Huiliang Wang and Hugh R. Brown

      Version of Record online: 3 DEC 2003 | DOI: 10.1002/pola.11022

      Thumbnail image of graphical abstract

      The UV-initiated grafting of methacrylic acid (MAA) and acrylic acid (AA) onto high-density polyethylene (PE) was studied in a range of solvents. Aliphatic solvents were found to be effective when used with a photoinitiator. Acetone could initiate the photografting of both MAA and AA onto PE when it was mixed with water; the maximum efficiency was found with about 40% acetone in the mixture. For AA, the optimum acetone/water concentration was 10%.

    5. UV grafting of methacrylic acid and acrylic acid on high-density polyethylene in different solvents and the wettability of grafted high-density polyethylene. II. Wettability (pages 263–270)

      Huiliang Wang and Hugh R. Brown

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.11010

      Thumbnail image of graphical abstract

      Information on the morphology of grafted layers was obtained by examining their water wettability, which is strongly influenced by the nature of the grafting solvent. The contact angle on samples grafted in acetone/water solutions was very low. For the polyethylene (PE) samples grafted in aliphatic solvents, the contact angle decreased only slightly from that observed on pure PE. The PE films grafted in these organic solvents also took a much longer time than films grafted in acetone/water solution to obtain a lower equilibrium water absorbency. For the solvents other than acetone/water, the grafted layer must be partially buried below the surface of PE.

    6. Synthesis of transparent thermoplastic polyurethane elastomers (pages 271–278)

      Mark F. Sonnenschein, Nelson Rondan, Benjamin L. Wendt and J. Mark Cox

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.11017

      Thumbnail image of graphical abstract

      Thermoplastic polyurethanes were synthesized from poly(propylene glycol)-block-poly(ethylene glycol) polyols and hybrid hard segments that combined at least two different chain extenders. The combination of hard segments allowed for modification of elastomer performance and processing not achievable by any single hard segment. The combination of hard segments modulated hard-segment energies that were directly related to elastomer performance. Special attention is paid to obtaining optically transparent elastomers with this technique.

    7. Development of novel flame-retardant thermosets based on benzoxazine–phenolic resins and a glycidyl phosphinate (pages 279–289)

      M. A. Espinosa, V. Cádiz and M. Galiá

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.10997

      Thumbnail image of graphical abstract

      Modified novolac resins with benzoxazine rings were prepared and copolymerized with a glycidyl phosphinate. Their curing behavior and the thermal properties of the curing resins were studied. Phenolic novolac resin acts as an initiator but p-toluensulfonic acid had to be used to decrease the curing temperature and to prevent glycidyl phosphinate from isomerizing. The materials obtained exhibited high glass-transition temperatures and retardation on thermal degradation rates. V-0 materials were obtained when the materials were tested for ignition resistance with the UL-94 test.

    8. Synthesis and characterization of new segmented polyurethanes with side-chain, liquid-crystalline chain extenders (pages 290–302)

      Fang-Jung Huang and Tzong-Liu Wang

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.11013

      Thumbnail image of graphical abstract

      Liquid-crystalline, segmented polyurethanes with methoxy–biphenyl mesogens pendant on the chain extender were synthesized by the conventional prepolymer technique and esterification reaction. Two, side-chain, liquid-crystalline (SCLC) polyurethanes with mesogens having spacers of six and eight methylene units were prepared. The structures of mesogenic units and SCLC polyurethanes were confirmed by Fourier transform infrared spectroscopy and 1H NMR. Polymer properties were also examined by solubility tests, water uptakes, and inherent viscosity measurements. Differential scanning calorimetry studies, wide-angle X-ray diffraction, and polarized optical microscopy investigations exhibited thermotropic liquid-crystalline behavior and nematic mesophases for both SCLC polyurethanes. Thermogravimetric analysis indicated that the presence of mesogenic side chains may increase the thermal stability of segmented polyurethanes.

    9. Poly[(2-alkoxy-5-methyl-1,3-phenylene vinylene)-alt-(phenylene vinylene)] derivatives with different contents of cis- and trans-olefins: The effect of the olefin bond geometry and conjugation length on luminescence (pages 303–316)

      Liang Liao, Liming Ding, Frank E. Karasz and Yi Pang

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.11021

      Thumbnail image of graphical abstract

      Poly(1,4-phenylene vinylene)s with different cis/trans-vinylene ratios were synthesized with the Wittig and Wittig—Horner reactions, the chromophore of which can be represented as 5. Although the cis/trans-vinylene ratio had a negligible impact on the emissive color of the polymers, the vinylene bond geometry could significantly affect the luminescence efficiency of the materials. The results from both photoluminescence and electroluminescence studies suggested that a trans-CH[DOUBLE BOND]CH configuration was desirable for achieving the optimal luminescence efficiency.

    10. Synthesis of random terpolymers and determination of reactivity ratios of N-carboxyanhydrides of leucine, β-benzyl aspartate, and valine (pages 317–325)

      Andrea Wamsley, Bhaskara Jasti, Pasit Phiasivongsa and Xiaoling Li

      Version of Record online: 4 DEC 2003 | DOI: 10.1002/pola.11020

      Thumbnail image of graphical abstract

      The copolymerization and terpolymerization of leucine-N-carboxyanhydride, β-benzyl aspartate- N-carboxyanhydride, and valine-N-carboxyanhydride were investigated to determine the random nature of the terpolymer compositions. The reactivity ratio of each monomer was determined with Fineman–Ross, Kelen–Tüdös, and nonlinear least-squares curve- fitting methods. The products of the estimated reactivity ratios indicated that random polymers were predominantly formed.

    11. Self-organized liquid-crystalline polyethers obtained by grafting tapered mesogenic groups onto poly(epichlorohydrin): Toward biomimetic ion channels 2 (pages 326–340)

      Joan Carles Ronda, José Antonio Reina and Marta Giamberini

      Version of Record online: 5 DEC 2003 | DOI: 10.1002/pola.11016

      Thumbnail image of graphical abstract

      A set of high-molecular-weight, new side-chain liquid crystalline polyethers was obtained by chemical modification of poly(epichlorohydrin) (PECH) with potassium 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy]benzoate. The resulting random-grafted copolymers had a hexagonal columnar mesophase with the tapered groups tilted with respect to the column axes.

    12. Thermoplastic poly(ester-imide)s derived from anhydride-terminated polyester prepolymer and diisocyanate (pages 341–350)

      P. Banu and Ganga Radhakrishnan

      Version of Record online: 5 DEC 2003 | DOI: 10.1002/pola.11018

      Thumbnail image of graphical abstract

      Thermoplastic poly(ester-imide)s were synthesized for the first time from anhydride-terminated polyester prepolymer and diisocyanate. The polyester prepolymer was synthesized from two different polyols and pyromellitic dianhydrides. Polymers based on polyether polyol exhibited phase-separated morphology.

    13. Effect of phenol and derivatives on atom transfer radical polymerization in the presence of air (pages 351–359)

      Yves Gnanou and Gürkan Hizal

      Version of Record online: 5 DEC 2003 | DOI: 10.1002/pola.11003

      Thumbnail image of graphical abstract

      The various phenolic compounds in conjunction with Cu(II) or Cu(I)-N,N,N′,N″,N″-pentamethyl diethylenetriamine complexes were used to initiate atom transfer radical polymerization (ATRP) of methyl methacrylate, styrene, and methyl acrylate in the presence of a limited amount of air at temperatures in the range of 80 to 110 °C. In this respect, sodium phenoxide (PhONa) was found to be a more effective additive, whereas p-nitrophenol was the least one. The obtained polymers displayed the common features of a controlled polymerization such as molecular weight control and low polydispersity index value (Mw/Mn < 1.5).

    14. Synthesis and association of poly(N,N-dimethylacrylamide) copolymers with perfluorocarbon pendent groups connected through polyethylene-glycol tethers (pages 360–373)

      Jie Da and Thieo E. Hogen-Esch

      Version of Record online: 8 DEC 2003 | DOI: 10.1002/pola.10796

      Thumbnail image of graphical abstract

      The synthesis is reported of copolymers of N,N-dimethylacrylamide (DMA) and methacrylates containing 1,1-dihydroperfluorodecanoyl (RF) groups separated from the methacrylate by long polyethylene glycol (PEG) spacer groups (between 1000 and 14,000 Da). At concentrations of between 1 and 8 wt % the copolymers with macromonomer contents of 1 mol % or less give gels in organic solvents such as dioxane, THF, or methanol, as well as in water. Copolymer association and gel formation is greatly enhanced in the presence of longer PEG spacers and higher comonomer content. This is consistent with fluorophilic association mediated by the formation of perfluorocarbon domains involving very small numbers of perfluorocarbon groups. This is consistent with smaller excluded volume effects mediated by the longer RF-end-functionalized PEG spacers and possibly by the incompatibility of PEG and PDMA, which may lead to the formation of PEG microdomains that increases the local concentrations of the RF groups.

    15. Polymeric ruthenium bipyridine complexes: New potential materials for polymer solar cells (pages 374–385)

      Veronica Marin, Elisabeth Holder and Ulrich S. Schubert

      Version of Record online: 5 DEC 2003 | DOI: 10.1002/pola.11024

      Thumbnail image of graphical abstract

      A bipyridine side-chain-functionalized poly(methyl methacrylate) was synthesized and characterized with NMR, IR, and ultraviolet–visible spectroscopy as well as gel permeation chromatography. Different ruthenium bipyridine precursor complexes were grafted onto this copolymer yielding a new class of graft copolymers with favorable photophysical and photochemical properties for the solar-cell applications.

SEARCH

SEARCH BY CITATION