Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 48 Issue 5

1 March 2010

Volume 48, Issue 5

Pages 997–1250

  1. Articles

    1. Top of page
    2. Articles
    1. Polymer-based fluorescence sensors incorporating chiral binaphthyl and benzo[2,1,3]thiadiazole moieties for Hg2+ detection (pages 997–1006)

      Xiaobo Huang, Jie Meng, Yu Dong, Yixiang Cheng and Chengjian Zhu

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23843

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      P-1, P-2, and P-3 can show pale red, blue–green, and orange fluorescence. Compared with other cations, such as Co2+, Ni2+, Ag+, Cd2+, Cu2+, and Zn2+, Hg2+ can exhibit the most pronounced fluorescence response of these polymers. P-1 and P-2 show obvious fluorescence quenching effect upon addition of Hg2+, on the contrary, P-3 shows fluorescence enhancement. Three polymer-based fluorescent sensors also show excellent fluorescence response for Hg2+ detection without interference from other metal ions.

    2. Proline-based polymeric monoliths: Synthesis, characterization, and applications as organocatalysts in aldol reaction (pages 1007–1015)

      Dipti Garg, J.-H. Ahn and Ghanshyam S. Chauhan

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23845

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      Proline-based polymer monoliths were synthesized via green protocol using lipase-catalyzed esterification of methacrylic acid and 4-hydroxyproline. The monomer was polymerized to polymer monoliths, and the latter were used as heterogeneous polymer catalysts in the aldol reaction that was studied in three forms viz. simple aldol, cross aldol, and ketone-aldehyde reaction. The catalysts exhibited high efficiency in the cross aldol reaction, especially with the aromatic substrates having electron withdrawing substituent, and reasonable retention of catalytic efficiency up to five cycles.

    3. Interactions of carbon nanotubes with pyrene-functionalized linear-dendritic hybrid polymers (pages 1016–1028)

      Greg J. Bahun and Alex Adronov

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23855

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      A series of linear-dendritic hybrid polymers, containing pyrene units at the periphery of aliphatic polyester dendrons, were prepared and found effective for dispersing single-walled carbon nanotubes (SWNTs) and multiwalled carbon nanotubes in organic solvent. It was found that a minimum of four pyrene units (second generation dendron), and a polymer length of ∼10 kDa, was necessary to form a strong enough interaction with SWNTs and enable steric stabilization in solution.

    4. Kinetics of the radical copolymerization of 2,2,2-trifluoroethyl methacrylate with tert-butyl α-trifluoromethacrylate (pages 1029–1037)

      Frédéric Boschet, Georgi Kostov, Bruno Ameduri, Toru Yoshida and Kosuke Kawada

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23857

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      The radical copolymerization and homopolymerization of 2,2,2-trifluoroethyl methacrylate (TFEMA) and tert-butyl α-trifluoromethacrylate (TBTFMA) in solution was investigated. The resulting statistic poly(TFEMA-co-TBTFMA) copolymers were characterized by NMR spectroscopy to assess their compositions. Reactivity ratios were assessed (rTFEMA = 4.87 ± 1.50 and rTBTFMA= 0.10 ± 0.02 at 74 °C) indicating the higher reactivity of methacrylate compared to α-trifluoromethacrylate. Yields, molecular weights and thermostability, increased with the TFEMA content.

    5. The effect of different catalytic chain transfer agents on particle nucleation and the course of the polymerization in ab initio batch emulsion polymerization of methyl methacrylate (pages 1038–1048)

      Niels M. B. Smeets, Tom G. T. Jansen, Timo J. J. Sciarone, Johan P. A. Heuts, Jan Meuldijk and Alex M. Van Herk

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23858

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      Proper control of the average molecular weight in emulsion polymerization can be achieved with different catalytic chain transfer agents (CCTAs). However, as CCTAs possess a range of intrinsic activities and partition coefficients, differences in the course of the polymerization and the final latex properties in terms of the particle size distribution are observed. The reported results contribute to a fundamental understanding of the application of catalytic chain transfer in emulsion polymerization. Furthermore, it is illustrated that the partitioning behavior is a key reaction parameter that governs the final latex properties and the course of the polymerization.

    6. Synthesis of well-defined rod-coil block copolymers containing trifluoromethylated poly(phenylene oxide)s by chain-growth condensation polymerization and atom transfer radical polymerization (pages 1049–1057)

      Yun Jun Kim, Myungeun Seo and Sang Youl Kim

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23859

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      Well-defined trifluoromethylated poly(phenylene oxide)s were synthesized via nucleophilic aromatic substitution (SNAr) reaction by a chain-growth polymerization manner. Synthesized poly(phenylene oxide)s were converted into macroinitiators for atom transfer radical polymerization (ATRP) and synthesis of well-defined rod-coil block copolymers was demonstrated via ATRP in the presence of the poly(phenylene oxide) macroinitiators.

    7. Chromatographic performance of molecularly imprinted polymers: Core-shell microspheres by precipitation polymerization and grafted MIP films via iniferter-modified silica beads (pages 1058–1066)

      Francisco Barahona, Esther Turiel, Peter A. G. Cormack and Antonio Martín-Esteban

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23860

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      Two different surface imprinting formats have been evaluated using thiabendazole as model template. The first format is a thin film of molecularly imprinted polymer (MIP) grafted from preformed silica particles using an immobilized iniferter-type initiator. The second format is MIP microspheres with narrow particle size distribution and core-shell morphology prepared by precipitation polymerization in a two-step procedure. From this study it can be concluded that grafted MIP beads can be obtained in a simple and direct manner, consuming only a fraction of the reagents used typically to prepare imprinted particles from a monolithic imprinted polymer.

    8. Multifunctional poly(2,5-benzimidazole)/carbon nanotube composite films (pages 1067–1078)

      Ji-Ye Kang, Soo-Mi Eo, In-Yup Jeon, Yeong Suk Choi, Loon-Seng Tan and Jong-Beom Baek

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23862

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      Multifunctional poly(2,5-benzimidazole) (ABPBI)/carbon nanotube (CNT) composites were prepared via in situ polymerization of 3,4-diaminobenzoic acid dihydrochloride in the presence of single-walled carbon nanotube (SWCNT) or multiwalled carbon nanotube (MWCNT) in a mildly acidic polyphosphoric acid (PPA). The resultant coagulated ABPBI/SWCNT and ABPBI/MWCNT composite films displayed outstanding physical properties with toughness of ∼200 MPa, a value that was close to the nature's toughest spider silk (215 MPa). They showed electrical conductivity of 9.10 × 10−5 and 2.53 × 10−1 S/cm, respectively, 1–4 orders of magnitudes higher than that of ABPBI film. Without acid doping, the composite films were also proton conducting with maximum conductivities of 0.017–0.018 S/cm.

    9. Biocompatible and pH-responsive triblock copolymer mPEG-b-PCL-b-PDMAEMA: Synthesis, self-assembly, and application (pages 1079–1091)

      Wenling Zhang, Jinlin He, Zhuang Liu, Peihong Ni and Xiulin Zhu

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23863

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      A new class of biocompatible and pH-sensitive triblock copolymers were synthesized, and their self-assembly behavior was investigated by the combination of fluorescence probe method, transmission electron microscopy, and light scattering analysis. The results showed that the triblock copolymers can self-assemble into micelles or vesicles in aqueous solution, depending on the copolymer composition, and their critical aggregation concentrations (CACs) are strongly dependent on the copolymer composition and pH values of media. Cell toxicity test indicated that these cationic block copolymers displayed lower in vitro cytotoxicity than that of branched PEI (25 kDa). Furthermore, the preliminary research was carried out to study the potential applications of these cationic aggregates in DNA binding and drug release.

    10. Titanium-mediated [CpTiCl2(OEt)] ring-opening polymerization of lactides: A novel route to well-defined polylactide-based complex macromolecular architectures (pages 1092–1103)

      Nikolaos Petzetakis, Marinos Pitsikalis and Nikos Hadjichristidis

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23864

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      Cyclopentadienyl ethoxy titanium dichloride, CpTiCl2(OEt), containing a 5% excess CpTiCl3, has proven to be a very efficient catalyst for the ring-opening polymerization (ROP) of L-lactide (LLA) in toluene at 130 °C. Based on the aforementioned results, PS-b-PLLA, PI-b-PLLA, and PEO-b-PLLA block copolymers [PS: polystyrene, PI: polyisoprene, and PEO: poly(ethylene oxide)] and a PS-b-PI-b-PLLA triblock terpolymer were synthesized. A graft copolymer consisting of poly(methyl methacrylate), PMMA, backbone with PLLA branches, PMMA-g-PLLA, was also synthesized using the macromonomer method.

    11. Novel diblock copolymer-grafted multiwalled carbon nanotubes via a combination of living and controlled/living surface polymerizations (pages 1104–1112)

      Dimitrios Priftis, Georgios Sakellariou, Jimmy W. Mays and Nikos Hadjichristidis

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23865

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      Diels-Alder cycloaddition reactions were used to functionalize multiwalled carbon nanotubes (MWNTs) with 1-benzocylcobutene-1'-phenylethylene or 4-hydroxyethylbenzocyclobutene. After appropriate transformations/additions, the functionalized MWNTs were used for surface initiated anionic and ring opening polymerizations of ethylene oxide and ε-caprolactone, respectively. The OH-end groups were transformed to isopropylbromide groups by reaction with 2-bromoisobutyryl bromide, for subsequent atom transfer radical polymerization of styrene or 2-dimethylaminoethyl methacrylate to afford the final diblock copolymers. 1H NMR, differential scanning calorimetry, thermogravimetric analysis, and transmission electron microscopy were used for the characterization of the nanocomposite materials.

    12. Bis(β-ketoamino)copper(II)/methylaluminoxane systems for homo- and copolymerizations of methyl acrylate and 1-hexene (pages 1113–1121)

      Haiyang Gao, Xiaofang Liu, Lixia Pei and Qing Wu

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23867

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      Bis(β-ketoamino)copper complexes activated with methylaluminoxane (MAO) can polymerize methyl acrylate (MA) to produce the syndio-rich atactic poly(methyl acrylate). Copolymerizations of MA and 1-hexene with copper(II)/MAO produced acrylate-enriched copolymers (MA > 80%) with isolated hexenes in the backbone. An insertion-triggered radical mechanism for polymerization was proposed.

    13. Vanadium(V) complexes containing tetradentate amine trihydroxy ligands as catalysts for copolymerization of cyclic olefins (pages 1122–1132)

      Ji-Qian Wu, Jing-Shan Mu, Sen-Wang Zhang and Yue-Sheng Li

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23868

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      A series of new vanadium(V) complexes bearing tetradentate amine trihydroxy ligands have been synthesized, structurally characterized, and investigated as the efficient catalysts for ethylene polymerization, ethylene/norbornene copolymerization, and ethylene/5-norbornene-2-methanol copolymerization.

    14. Epoxy-based networks combining chemical and supramolecular hydrogen-bonding crosslinks (pages 1133–1141)

      Damien Montarnal, François Tournilhac, Manuel Hidalgo and Ludwik Leibler

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23870

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      Supramolecular chemistry of heterocyclic ureas and chemistry of epoxides are combined in a two-step procedure to synthesize new crosslinked materials incorporating both chemical and supramolecular hydrogen-bond links. The density of both chemical and physical crosslinks is controlled by the stoichiometry of the reactants and the use of a proper catalyst to limit side reactions. Depending on the stoichiometry, chemically and thermally stable materials can be attained with a wide range of thermomechanical properties. The method can be used to produce elastomeric objects of complex shapes.

    15. Behaviors of self-assembled diblock copolymer with pendant photosensitive azobenzene segments (pages 1142–1148)

      Jui-Hsiang Liu and Yi-Hong Chiu

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23871

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      Reverse micelles with spherical construction were obtained in the condition of 2 wt % PMMA-b-PAzoMA in THF/H2O = 1:2. UV irradiation caused a deformation of the nanoparticles. As seen in the figures, after UV exposure, rod-like particles were formed. In addition, the rod-like particles were converted to spherical constructions when the sample was exposed to a sunlight lamp and then kept at 30 °C for 2 h with violent stirring. After UV irradiation, hydrophilicity of the PAzoMA of the diblock copolymer could be changed leading to the aggregation of micelles and then the deformation of the aggregated spheres to rod-like construction.

    16. Tailoring the liquid crystalline property via controlling the generation of dendronized polymers containing azobenzene mesogen (pages 1149–1159)

      Chang-An Yang, Guo Wang, Helou Xie, Qing Wang, Hailiang Zhang, Erqiang Chen and Qifeng Zhou

      Article first published online: 22 JAN 2010 | DOI: 10.1002/pola.23873

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      The polymer PG2 exhibits smectic phase structure below 155 °C (a) and columnar nematic phase structure above 155 °C (b).

    17. Density functional study for the polymerization of ethylene monomer using a new nickel catalyst (pages 1160–1165)

      Javier Ramos, Víctor L. Cruz, Javier Martínez-Salazar, Mikael Brasse, Pilar Palma and Juan Campora

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23874

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      We report a theoretical study for a new family of cationic nickel based catalysts for the ethylene polymerization. The only difference between the two catalysts studied in this work is the methyl substitution in the C imino ligand in one of the catalysts. This catalyst is less active than the unsubstituted one. We study the ethylene polymerization mechanism by DFT methods to understand this difference. The results agree with the experimental findings and suggest an explanation for their differential behavior.

    18. Synthesis and nonlinear optical properties of novel Y-type polyurethane containing tricyanovinylthiazole with enhanced thermal stability of second harmonic generation (pages 1166–1172)

      Hyo Jin No, Han-Na Jang, You Jin Cho and Ju-Yeon Lee

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23875

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      A new Y-type polyurethane 4 containing 5-methyl-4-{5-(1,2,2-tricyanovinyl)-2-thiazolylazo}resorcinoxy groups as NLO chromophores was prepared. The resulting polyurethane 4 has a thermal stability up to 250 °C with Tg value around 118 °C. The SHG coefficient (d33) of poled polymer film at 1560 nm fundamental wavelength is around 8.43 × 10−9 esu. The polymer exhibits a SHG thermal stability even at 12 °C higher than Tg, and there is no SHG decay below 130 °C. This enhanced thermal stability of optical nonlinearity stems from the stabilization of dipole alignment of the NLO chromophores, which are part of the polymer main chain.

    19. N-vinylcaprolactam-based microgels for biomedical applications (pages 1173–1181)

      Ainara Imaz and Jacqueline Forcada

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23876

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      Three types of poly(N-vinylcaprolactam)-based temperature-sensitive microgel particles were synthesized by emulsion polymerization. The uptake of a model drug (calcein) into the particles was analyzed in terms of the amount of calcein absorbed and equilibrium–swelling degree. By incubating the microgels with primary neuronal cell cultures of embrionary rats, cell viability and biocompatibility tests were carried out. The results show that the driving force for the model drug to penetrate into the microgel particles is H-bonding associations. On the other hand, cell death was microgel concentration and incubation period dependent. Microgels can be stored in a dried state and resuspended in water when necessary without changing their swelling–deswelling ability.

    20. A novel thermotropic liquid crystalline copolyester containing phosphorus and aromatic ether moity toward high flame retardancy and low mesophase temperature (pages 1182–1189)

      Xiang-Cheng Bian, Li Chen, Jun-Sheng Wang and Yu-Zhong Wang

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23878

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      A series of liquid crystalline polyesters containing phosphorus and aromatic ether groups (TLCP-AEs) were synthesized from p-acetoxybenzoic acid (p-ABA), terephthalic acid (TPA), 4,4′-oxybis(benzoic acid) (OBBA), and acetylated 2-(6-oxid-6H-dibenz(c,e) (1,2) oxaphosphorin 6-yl) 1,4-benzenediol (DOPO-AHQ) by melting transesterification. TLCP-AEs showed typical nematic mesophase ranging from 230 °C to above 400 °C, and had excellent thermal stability and flame retardancy. Their 5% weight loss temperatures were above 440 °C and the char yields at 700 °C were higher than 40 wt %.

    21. SET-LRP of acrylates in air (pages 1190–1196)

      Sven Fleischmann, Brad M. Rosen and Virgil Percec

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23879

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      SET-LRP of MA was performed in the presence of air. The polymerization tolerated aerobic conditions and proceeded after a short induction period, but with moderately lower kpapp than when thorough degassing was employed. The addition of a small amount of hydrazine hydrate eliminated the induction period and the polymerization proceeded with the same kpapp as for carefully degassed reaction mixtures. In DMSO and MeOH the Cu(0) generated by hydrazine reduction of Cu2O acted as an oxygen scavenger, providing PMA with predictable molecular weight, narrow molecular weight distribution and high chain end fidelity in short time without the need for careful deoxygenation.

    22. Host–guest complexation-triggered chiroptical change of poly(phenylacetylene)s bearing binaphthocrown ether moieties on the main chain (pages 1197–1206)

      Ryosuke Sakai, Takafumi Yonekawa, Issei Otsuka, Ryohei Kakuchi, Toshifumi Satoh and Toyoji Kakuchi

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23881

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      Diacetylene monomers with respective lengths of the oxyethylene chains have been designed and cyclopolymerized to produce novel poly(phenylacetylene)s bearing a different cavity size of the chiral crown ether in the repeating units. A circular dichroism analysis revealed that the polymers possessed a helical structure with an excess single screw sense induced by the covalently bonded binaphthyl units. The host–guest complexation of the polymers with both achiral and chiral guests produced a chiroptical change based on the fluctuation in the main chain conformation.

    23. Synthesis of dual pH/temperature-responsive polymers with amino groups by living cationic polymerization (pages 1207–1213)

      Yukari Oda, Shokyoku Kanaoka and Sadahito Aoshima

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23882

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      Well-defined dual stimuli-responsive block copolymers having a pH-responsive polyamine segment and a thermosensitive segment were synthesized by base-assisting living cationic polymerization. The precision synthesis of primary amino functional polymers could be achieved only by attaining fine control of cationic polymerization of a phthalimide-containing vinyl ether monomer precursor, 2-vinyloxyethyl phthalimide using a base-assisting initiating system, which was difficult using any other initiating system. The product diblock copolymers self-assembled in water in response to both pH and temperature.

    24. Bio-safe synthesis of linear and branched PLLA (pages 1214–1219)

      Sofia Målberg, Dildare Basalp, Anna Finne-Wistrand and Ann-Christine Albertsson

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23884

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      Bi(III) acetate and creatinine are considered biologically safe and appear to have a big potential as catalytic systems for the synthesis of linear and branched poly(L-lactide). Their catalytic efficiencies have been compared with lipase PS and stannous (II) ethylhexanoate.

    25. Poly(n-alkylsilsesquioxane)s: Synthesis, characterization, and modification with poly(dimethylsiloxane) (pages 1220–1229)

      Luís A. S. A. De Prado, Iris L. Torriani and Inez V. P. Yoshida

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23885

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      The present publication reports the synthesis of self-supported poly(n-alkylsilsesquioxane) films, bearing n-octyl or n-dodecyl groups, through a solvent-free sol-gel process. The dibutyltin diacetate catalyst, utilized for the polycondensation of n-octyltriethoxysilane or n-dodecyltriethoxysilane, lead to an efficient condensation reaction (as evidenced by solid-state 29Si-NMR). The films exhibited excellent thermal stability, which makes them potential candidates to protective coatings. SAXS and WAXS evidenced an amorphous behavior for all these materials. The poly(n-alkylsilsesquioxanes) were modified by poly(dimethylsiloxane). The resulting polymeric networks were more flexible, but kept the outstanding thermal stability, typical of polysilsesquioxane polymers.

    26. Titanium complexes of dialkanolamine ligands as initiators for living ring-opening polymerization of ε-caprolactone (pages 1230–1240)

      Yulia A. Piskun, Irina V. Vasilenko, Sergei V. Kostjuk, Kirill V. Zaitsev, Galina S. Zaitseva and Sergei S. Karlov

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23886

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      A series of novel titanium complexes with one (titanocanes) and two (spirobititanocanes) dialkanolamine ligands were investigated in the ring-opening polymerization (ROP) of ε-caprolactone. Titanocanes initiated living ROP of ε-caprolactone affording polymers with Mn ≤ 30,000 g mol−1 and narrow MWD (Mw/Mn ≤ 1.3), while higher molecular weight polymers (Mn ≤ 70,000 g mol−1) with reasonable MWD (Mw/Mn ≤ 1.6) can be obtained in the presence of spirobititanocanes as initiators.

    27. Synthesis and solution behavior of comb-like terpolymers with poly(ethylene oxide) macromonomer (pages 1241–1250)

      Chuanrong Zhong, Liufeng Jiang and Xiuhua Peng

      Article first published online: 25 JAN 2010 | DOI: 10.1002/pola.23888

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      A novel comb-like associating terpolymer (PVEA) were synthesized by copolymerizing acrylamide, sodium 2-acrylamido-2-methylpropane sulphonate (NaAMPS) and a novel macromonomer p-vinylbenzyl-terminated octylphenoxy poly(ethylene oxide) with the PEO chain length of 18 (VBPEO). The expanded polymer chains aggregated with each other to form the interesting structures in water, and the continuous network structures of the polymer in the brine solution were still formed. This resulted in the unique solution properties of PVEA such as both excellent uni- and bi-valent cation resistance, salt- and heat-thickening twice, pseudoplastic behavior, and thixotropy.