Journal of Polymer Science Part A: Polymer Chemistry

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

15 September 2003

Volume 41, Issue 18

Pages 2743–2904

  1. Articles

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    2. Articles
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    4. Articles
    1. Self-polyaddition of triethylsilyl perfluoroisopropenyl ether (pages 2743–2754)

      Hirotada Fujiwara, Tadashi Narita and Hiroshi Hamana

      Version of Record online: 29 JUL 2003 | DOI: 10.1002/pola.10819

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      The results on the radical self-polyaddition reactivity of two trialkylsilyl perfluoroisopropenyl ethers, triethysilyl perfluoroisopropenyl ether [CF2[DOUBLE BOND]C(CF3)OSi(C2H5)3] (FTEE) and dimethylphenylsilyl perfluoroisopropenyl ether [CF2[DOUBLE BOND]C(CF3)OSi(CH3)2 C6H5], and two perfluoroisopropenyl carboxylates, 2-butyroxypentafluoropropene [CF2[DOUBLE BOND]C(CF3)OCOC3H7] and 2-(methoxyacetoxy)pentafluoropropene [CF2[DOUBLE BOND]C(CF3)OCOCH2OCH3], are described. Radical self-polyaddition of FTEE afforded a polymer as high as 1.87 × 104 in molecular weight in the presence of radical generators such as benzoyl peroxide and di-tert-butyl peroxide.

    2. Synthesis and properties of the ionomer diblock copolymer poly(4-vinylbenzyl triethyl ammonium bromide)-b-polyisobutene (pages 2755–2764)

      Yuhong Ma, Guangying Wu and Wantai Yang

      Version of Record online: 28 JUL 2003 | DOI: 10.1002/pola.10815

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      A novel diblock copolymer, one block being polyisobutene and the other block containing ammonium bromide, was synthesized by the chemical modification of poly(4-methylstyrene)-b-polyisobutene. The results demonstrated that the solubility, microphase-separation structures, and thermomechanical behavior of the obtained poly(4-vinylbenzyl triethyl ammonium bromide)-b-polyisobutene were quite different from those of their parent block copolymer.

    3. Luminescent copoly(aryl ether)s consisting of alternate oxadiazole and 1,4-distyrylbenzene derivatives: Synthesis and characterization (pages 2765–2777)

      Yun-Hao Yu and Yun Chen

      Version of Record online: 28 JUL 2003 | DOI: 10.1002/pola.10825

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      Four copoly(aryl ether)s (P1P4) consisting of alternate electron-transporting (oxadiazole) and emitting chromophores (distyrylbenzene) have been synthesized from bis(fluoride) and bis(phenol) monomers. Their photoluminescence spectra and quantum yields are dependent on the composition of the two isolated fluorophores. The HOMO and LUMO energy levels have been estimated electrochemically. All the observations directly prove that oxidation starts at emitting (hole-transporting) segments. Moreover, incorporation of bisoxadiazole unit increases the electron affinity and reduces the turn-on electric field better than one oxadiazole unit. The P1, P2 revealed blue and P3, P4 revealed purple-blue electroluminescence.

    4. Essential role of chain ends in the nylon-6/poly(ethylene terephthalate) exchange (pages 2778–2793)

      Filippo Samperi, Concetto Puglisi, Rossana Alicata and Giorgio Montando

      Version of Record online: 28 JUL 2003 | DOI: 10.1002/pola.10823

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      The exchange reactions that occur during the melt mixing of equimolar blend of Nylon6 (Ny6) and poly(ethylene terephthalate) (PET) at 285 °C, with and without catalytic amount of p-toluene sulfonic acid (TsOH), were studied by a combination of NMR and Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI) techniques. Our results show that TsOH is able to react with the PET sample yielding PET chains terminated with carboxyl groups (Scheme 1), which then react with the amide groups of the Ny6 giving Ny6-PET copolyesteramde and carboxyl terminated Ny6 chains. The structural identification by means of MALDI and NMR tools of the melt mixed materials, as a function of the mixing time, show that a random copolyesteramide with an equimolar composition of Ny6 and PET units was formed after 180 min on heating. The results reveal the essential role of carboxyl end groups in the exchange reaction between Ny6 and PET, and allow a drawing of detailed mechanism for this reaction.

    5. Copolymerization of diglycidyl ether of bisphenol A with γ-butyrolactone catalyzed by ytterbium triflate: Shrinkage during curing (pages 2794–2808)

      Cristina Mas, Xavier Ramis, Josep Maria Salla, Ana Mantecón and Angels Serra

      Version of Record online: 29 JUL 2003 | DOI: 10.1002/pola.10826

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      The curing of diglycidyl ether of bisphenol A (DGEBA) and γ-butyrolactone (γ-BL), with ytterbium triflate as a catalyst, was studied with differential scanning calorimetry, Fourier transform infrared (FTIR), and thermomechanical analysis. FTIR studies confirmed that four elemental reactions took place during the curing process: the formation of a spiroorthoester (SOE) by the reaction of DGEBA with γ-BL, the homopolymerization of SOE, the homopolymerization of DGEBA, and the copolymerization of SOE and DGEBA. The curing occurred with little shrinkage after gelation because of the polymerization of SOE, with near-zero shrinkage in the last stages of the curing.

    6. Polymer proton-conduction systems based on commercial polymers. I. Synthesis and characterization of hydrogenated styrene–butadiene block copolymer and isobutylene isoprene rubber systems (pages 2809–2815)

      A. Nácher, P. Escribano, C. Del Río, A. Rodríguez and J. L. Acosta

      Version of Record online: 29 JUL 2003 | DOI: 10.1002/pola.10821

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      This work describes the synthesis and characterization of HSBR and HSBR/IIR. The films obtained were crosslinked, sulfonated, and microstructurally and electrically characterized. In additions water and methanol crossover was determined, the results being compared with those of Nafion 117.

    7. Graft copolymers by acyclic diene metathesis and atom transfer radical polymerization techniques (pages 2816–2827)

      Patrick M. O'Donnell and Kenneth B. Wagener

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10852

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      Precise graft copolymer structures (3) have been achieved through a macromonomer approach with the acyclic diene metathesis (ADMET) reaction. Properties such as composition and regularity of graft length were controlled through living atom transfer radical polymerization (ATRP) techniques. These copolymers lead to novel thermal behaviors different than the homopolymer of random copolymer.

    8. The reversible addition-fragmentation chain transfer process and the strength and limitations of modeling: Comment on “the magnitude of the fragmentation rate coefficient” (pages 2828–2832)

      Christopher Barner-Kowollik, Michelle L. Coote, Thomas P. Davis, Leo Radom and Philipp Vana

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10854

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      There is appreciable uncertainty concerning the magnitude of the fragmentation rate coefficient of the intermediate radical in reversible addition-fragmentation chain transfer (RAFT) polymerizations. A large proportion of the experimental and theoretical evidence suggests that it is a stable species with a lifetime longer than 0.0001 s. This is particularly the case when the intermediate macro-RAFT radical is stabilized by a phenyl group attached to the radical center or has a poor leaving group. Although the occurrence to some extent of irreversible termination reactions cannot be excluded, we argue that such reactions are more likely to be a result of slow fragmentation of the intermediate macro-RAFT radical.

    9. A difference of six orders of magnitude: A reply to “the magnitude of the fragmentation rate coefficient” (pages 2833–2839)

      Aileen R. Wang, Shiping Zhu, Yungwan Kwak, Atsushi Goto, Takeshi Fukuda and Michael S. Monteiro

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10853

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      The fragmentation reaction plays a fundamental role in controlling polymer molecular weight in a reversible addition–fragmentation transfer (RAFT) polymerization. However, there exists a six-order-of-magnitude difference in the reported values of the rate constant (kf: 10−2 versus 104/s) for virtually similar RAFT systems. The choices of the kf value in modeling give very different simulation results. The use of kf ∼ 10−2/s results in a calculated adduct radical concentration of 10−4 to 10−3 mol/L, contradictory to the reported experimental work in the range of <10−6 mol/L. The figure shows the calculated radical concentrations with different rate constants.

  2. Rapid Communication

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    3. Rapid Communication
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      Synthesis of a novel block copolymer containing aromatic polyamide and fluoroethylene segments (pages 2840–2845)

      Arata Korematsu, Tsutomu Furuzono and Akio Kishida

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10872

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      A novel block copolymer containing aromatic polyamide (aramid) and fluoroethylene segments was synthesized by a two-step, low-temperature solution polycondensation. In the first step, a telechelic diamine was prepared by the reaction of 3,4′-diaminodiphenylether and tetrafluorosuccinic acid in the presence of 1,3-dicyclohexylcarbodiimide as a condensing agent. Next, the block copolymer was synthesized by the polycondensation of the telechelic diamine and isophthaloyl chloride. The number-average molecular weight of this polymer, according to gel permeation chromatography, was over 1.7 × 104. Incorporating fluoroethylene segments improved the solubility of the resulting polymer with respect to conventional aramids.

  3. Articles

    1. Top of page
    2. Articles
    3. Rapid Communication
    4. Articles
    1. Design and synthesis of a thermally stable second-order nonlinear optical chromophore and its poled polymers (pages 2846–2853)

      Anjun Qin, Zhou Yang, Fenglian Bai and Cheng Ye

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10871

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      2,3-Bis(4-aminophenyl)-5,6-dicyanopyrazine was designed and synthesized, and the depoling onset temperatures of its donor-embedded polyimide (PI) and polyurea (PU) were as high as 200 °C.

    2. Synthesis of side-chain liquid-crystalline homopolymers and triblock copolymers with p-methoxyazobenzene moieties and poly(ethylene glycol) as coil segments by atom transfer radical polymerization and their thermotropic phase behavior (pages 2854–2864)

      Xiaohua He, Hailiang Zhang, Deyue Yan and Xiayu Wang

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10870

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      A series of homopolymers and triblock copolymer with p-methoxyazobenzene moieties and poly(ethylene glycol) (PEG) as coil segments were synthesized by atom transfer radical polymerization. Their structure characteristics were investigated with gel permeation chromatography, 1H NMR, and Fourier transform infrared spectra. The results of thermal investigation, obtained from differential scanning calorimetry and polarized optical microscopy, showed that the triblock copolymers exhibit mesophases similar to the homopolymers, a smectic phase, and a nematic phase, which cause the mesophase transition temperatures to increase and the crystallizability of the PEG block to decrease with increasing molecular weight of the liquid-crystalline block. However, the PEG blocks hardly affected the glass-transition temperature and phase-transition temperatures from the smectic to nematic phase and greatly reduced the phase-transition temperatures from the nematic to isotropic phase of the triblock copolymers.

    3. Studies on calcium-containing poly(urethane ether)s (pages 2865–2878)

      R. Jayakumar, Y.-S. Lee and S. Nanjundan

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10867

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      A series of calcium-containing poly(urethane ether)s (PUEs) of different compositions were synthesized with mono(hydroxyethoxyethyl)phthalate/poly(ethylene glycol) (PEG300 or PEG400)/diisocyanate [hexamethylene diisocyanate (HMDI) or tolylene 2,4-diisocyanate (TDI)] molar ratios of 2:2:4, 3:1:4, and 1:3:4 with di-n-butyltin dilaurate as a catalyst. Blank PUEs without calcium-containing ionic diols were also prepared. The PUEs were well characterized by Fourier transform infrared, 1H and 13C NMR, solid-state cross-polarity/magic-angle-spinning 13C NMR, viscosity, solubility, thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction studies. The PUEs were applied as top coats on acrylic-coated leather, and their physicomechanical properties were also studied.

    4. Synthesis of amphiphilic poly(para-phenylene)s by Suzuki polycondensation (pages 2879–2889)

      Changmei Zhang, Helmut Schlaad and A. Dieter Schlüter

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10869

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      The synthesis and molar-mass determination of poly(para-phenylene)s (PPP) with one polar oligo(ethylene glycol) (OEG) and one unpolar hexoxy side chain at every other phenylene ring are reported. The OEG chains have three or five repeat units and are terminated by silyl-protecting or, after deprotection, free hydroxy groups. The PPPs reported here have the potential to segregate lengthwise into polar and unpolar domains, which makes them interesting constituents for novel self-assembled aggregates.

    5. Fluorinated vinyl ethers as new surface agents in the photocationic polymerization of vinyl ether resins (pages 2890–2897)

      R. Bongiovanni, M. Sangermano, G. Malucelli, A. Priola, A. Leonardi, B. Ameduri, A. Pollicino and A. Recca

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10896

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      The syntheses of fluorinated vinyl ethers (H2C[DOUBLE BOND]CHOCH2CH2CnF2n+1, n = 6 or 8) and their cationic photocopolymerizations with bis(4-vinyloxybutyl) isophthalate are reported. The cured films showed interesting surface properties in the presence of small amounts of fluoroadditives (<3 wt %): the air side of the networks was selectively modified and made hydrophobic.

    6. Synthesis and enzymatic degradation of 2-methylene-1,3-dioxepane and methyl acrylate copolymers (pages 2898–2904)

      L. F. Sun, R. X. Zhuo and Z. L. Liu

      Version of Record online: 1 AUG 2003 | DOI: 10.1002/pola.10868

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      Copolymers [P(MDOx-co-MA100−x)] with ester units in the backbone were synthesized by the free-radical copolymerization of 2-methylene-1,3-dioxepane (MDO) and methyl acrylate (MA). The enzymatic degradation of the copolymers obtained was carried out in the presence of proteinase K or a crude enzyme extracted from earthworms. The results showed that the copolymers could enzymatically be degraded.

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