Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 45 Issue 9

1 May 2007

Volume 45, Issue 9

Pages 1575–1799

  1. Articles

    1. Top of page
    2. Articles
    1. Synthesis of polymeric core–shell particles using surface-initiated living free-radical polymerization (pages 1575–1584)

      Sarav B. Jhaveri, Damla Koylu, Dominik Maschke and Kenneth R. Carter

      Version of Record online: 9 MAR 2007 | DOI: 10.1002/pola.21977

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      Surfactant free emulsion polymerization of methyl methacrylate in presence of a crosslinking reagent has been used to in-situ crosslink colloid micelles to produce stable, crosslinked polymeric nanoparticles. A functionalized methacrylate monomer containing a dormant atom transfer radical polymerization (ATRP) living free radical initiator, termed inimer (initiator-/-monomer), has been added to the solution during the polymerization, to functionalize the surface of the crosslinked nanoparticles with ATRP initiator groups. Surface initiated ATRP of different monomers was then carried out to produce core-shell type polymeric nanostructures. The nanoparticles have been characterized using TEM, SEM, optical microscopy, dynamic light scattering and Raman spectroscopy.

    2. Block copolymers of dodecafluoroheptyl methacrylate and butyl methacrylate by RAFT miniemulsion polymerization (pages 1585–1594)

      Zhang Qinghua, Zhan Xiaoli, Chen Fengqiu, Shi Ying and Wang Qiongyan

      Version of Record online: 9 MAR 2007 | DOI: 10.1002/pola.21930

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      The reversible addition-fragmentation chain transfer minimulsion polymerization of butyl methacrylate (BMA) and dodecafluoroheptyl methacrylate (DFMA) was carried out with 2-cyanoprop-2-yl dithiobenzoate as chain transfer agent. The polymer molecular weights increased linearly with the monomer conversion. Synthesis of poly(BMA-b-DFMA) diblock copolymers with a regular structure (PDI < 1.30, PMMA calibration) was performed by adding DFMA at the end of the polymerization of BMA, and the PBMA macro-CTA was confirmed to be a good candidate to mediate a well-controlled reaction in block polymerization of DFMA.

    3. Synthesis, characterization, and biodegradation of copolymers of unsaturated and saturated poly(ester amide)s (pages 1595–1606)

      Kai Guo and C. C. Chu

      Version of Record online: 9 MAR 2007 | DOI: 10.1002/pola.21926

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      A new family of biodegradable copolymers of unsaturated poly(ester amide)s and saturated poly(ester amide)s based on L-phenylalanine, aliphatic dicarboxylic acids, and aliphatic dialcohols was synthesized by solution polycondensation and characterized. These unsaturated/saturated poly(ester amide) copolymers (USPEAs) were obtained in fairly good yields with N,N-dimethylacetamide as the solvent. The molecular weights (Mn and Mw) of the USPEAs measured by GPC ranged from 15 to 60 kg/mol with a molecular weight distribution of 1.07–1.63. The copolymers showed significant enzyme-catalyzed biodegradation, but the biodegradation in a pure phosphate buffered saline buffer was very slow. Upon the adjustment of the unsaturated-to-saturated diester monomer feed ratio, the obtained USPEA copolymers could have controlled chemical and physical properties, such as glass transition temperatures, solubility, and biodegradability, to meet a wide range of biomedical engineering and pharmaceutical applications.

    4. A comparative computational study of the homolytic and heterolytic bond dissociation energies involved in the activation step of ATRP and SET-LRP of vinyl monomers (pages 1607–1618)

      Tamaz Guliashvili and Virgil Percec

      Version of Record online: 9 MAR 2007 | DOI: 10.1002/pola.21927

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      The calculation of the bond dissociation energies of homolytic, inner-sphere electron-transfer responsible for ATRP, and heterolytic, outer-sphere single-electron-transfer responsible for SET-LRP, for dormant models of monomer and dimer halides is reported. Models include activated and non-activated monomers containing electron-withdrawing groups and a non-activated monomer containing an electron-donor group. Two examples of sulfonyl and N-halide initiators are also reported. This study demonstrated much lower bond dissociation energies for the heterolytic process and explains the higher rate constant of activation, the higher apparent rate constant of propagation, and the lower polymerization temperature for both activated and non-activated monomers containing electron-withdrawing groups in SET-LRP.

    5. Combined effects of conjugation pattern and alkoxy side chains on the photovoltaic properties of thiophene-containing PPE-PPVs (pages 1619–1631)

      Daniel Ayuk Mbi Egbe, Le Huong Nguyen, Kathy Schmidtke, Andreas Wild, Christoph Sieber, Serap Guenes and Niyazi Serdar Sariciftci

      Version of Record online: 9 MAR 2007 | DOI: 10.1002/pola.21928

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      Four thiophene-containing PPE-PPVs, PIa-b and PIIa-b, have been synthesized and characterized. Their photophysical, electrochemical, and photovoltaic properties have been discussed while focussing on the combined effects of backbone conjugated pattern and grafted alkoxy side chains. For instance, replacing 2-ethylhexyl in PIa with methyl in PIb leads to an increase of the power conversion efficiency from 1.2 to 1.7%. The same change is of insignificant effect in PII systems.

    6. New polyphenylene- and polyphenylenevinylene-based copolymers containing triarylpyrazoline units in the main chains (pages 1632–1640)

      Qiang Peng, Mingjun Li, Xinghua Tang, Shiqiang Lu, Junbiao Peng and Yong Cao

      Version of Record online: 13 MAR 2007 | DOI: 10.1002/pola.21929

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      Two novel poly(p-phenylenevinylene)- and poly(p-phenylene)-based copolymers containing triarylpyrazoline units in the main chains were successfully designed, synthesized, and characterized. The resulting copolymers were amorphous and showed excellent solubility in common organic solvents. They exhibited good photoluminescence properties with high photoluminescence efficiencies. Light-emitting-diode devices with an indium tin oxide/poly(3,4-ethylene dioxythiophene)/Polymer/Ba/Al configuration could emit strong green light with external quantum efficiencies of 0.53 and 0.92%.

    7. Pendent polyimides using mellitic acid dianhydride. II. Structure–property relationships for zirconium-containing pendent polymers (pages 1641–1652)

      Marvin L. Illingsworth, Huixiong Dai, Wei Wang, Derek Chow, Emilie J. Siochi, Kenwan Yang, Julie M. Leiston-Belanger and Jennifer Jankauskas

      Version of Record online: 13 MAR 2007 | DOI: 10.1002/pola.21931

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      Using mellitic acid dianhydride (MADA) to prepare Zr-pendent co-polyimides is being evaluated as a means of increasing Zr concentration and atomic oxygen resistance. A structure-property study has been performed using PMDA and OPDA (dianhydrides) and 4,4′-ODA, 3,4′-ODA, and 1,3-APB (diamines) as starting materials, and holding the Zr concentration at 10% (mol). The spectroscopic data for all products are consistent with the expected structures. Zr-pendent and nonpendent co-polyamic acid precursors had intrinsic viscosities (η0) of 0.86–0.46 and 0.76–0.38 and weight average molecular weights (Mw) from GPC of 115,400–436,000 and 38,300–111,200 Da, respectively.

    8. Controlled grafting of ethyl cellulose with azobenzene-containing polymethacrylates via atom transfer radical polymerization (pages 1653–1660)

      Xinde Tang, Longcheng Gao, Xinghe Fan and Qifeng Zhou

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21932

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      Atom transfer radical polymerization (ATRP) was employed to synthesize the graft copolymers of ethyl cellulose with azobenzene-containing polymethacrylates as side chains. The hydroxyl groups on ethyl cellulose reacted with 2-bromoisobutyryl bromide to yield 2-bromoisobutyryloxy groups. The functionalized ethyl cellulose was used to initiate the polymerization of 6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate (MMAzo) in the presence of CuBr/N,N, N′,N″,N″-pentamethylenetriamine (PMDETA) as catalyst and anisole as solvent. The polymerizations proceeded with living/controlled character to yield the graft copolymers with relatively narrow polydispersity. These graft copolymers exhibit liquid crystalline property, and photoresponsive isomerization under the irradiation of UV–vis light.

    9. Tailor-made poly(ethyl acrylate) by atom transfer radical polymerization (pages 1661–1669)

      Haimanti Datta, Anil K. Bhowmick and Nikhil K. Singha

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21933

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      Ethyl acrylate (EA) was polymerized via atom transfer radical polymerization (ATRP) using different catalyst systems. By judicious choice of the reaction parameters it is possible to tailor the end group of the final polymer. MALDI-TOF-MS analysis and the chain extension experiment of PEA prepared using bpy as ligand showed the presence of [BOND]Br as the end group; use of PMDETA as ligand showed dead end polymer as the major species towards the end of polymerization.

    10. Thermally curable benzoxazine monomer with a photodimerizable coumarin group (pages 1670–1676)

      Baris Kiskan and Yusuf Yagci

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21934

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      A new monomer, 4-methyl-9-p-tolyl-9,10-dihydrochromeno[8,7-e][1,3]oxazin-2(8H)-one, possessing both benzoxazine and coumarin rings in its structure was synthesized by the reaction of 4-methyl-7-hydroxycoumarin, paraformaldehyde, and p-toluidine in methanol at 40 °C and characterized with spectral analysis. Upon photolysis around 300 nm, this monomer underwent dimerization via the [2πs+2πs] cycloaddition reaction. Photodimerization reactions were investigated with UV and 1H NMR spectroscopy measurements. The thermal ring-opening reaction of the benzoxazine ring was demonstrated with differential scanning calorimetry measurements. The thermal behavior of the cured product was also investigated with thermogravimetric analysis.

    11. A kinetic study of metallocene-catalyzed ethylene polymerization using different aluminoxane cocatalysts (pages 1677–1690)

      Deborah M. Sarzotti, Devin J. Marshman, William E. Ripmeester and João B. P. Soares

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21935

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      We investigated the kinetics of ethylene polymerization with Cp2ZrCl2 and four different types of aluminoxanes: methylaluminoxane (MAO), modified methylaluminoxanes with a fraction of methyl groups substituted with iso-butyl (MMAO-4) or octyl (MMAO-12) groups, and polymethylaluminoxane (PMAO-IP). The figure compares the polymerization rate profiles of these four aluminoxanes for [Al]/[Zr] = 5000. The polymers had polydispersities between 3 and 4, indicating the presence of more than one active site type. We proposed a mathematical model that uses an unstable active complex, formed in the early stages of polymerization, and transformed over time to a more stable active complex via an intermediate.

    12. Helical poly(phenylacetylene) derived from L-tyrosine: A promising candidate for functional helical polymers carrying transformable N- and C-termini (pages 1691–1698)

      Haichao Zhao, Fumio Sanda and Toshio Masuda

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21936

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      A novel optically active phenylacetylene derivative, N-(tert-butoxycarbonyl)-4-ethynyl-L-phenylalanine methyl ester, was synthesized from L-tyrosine and polymerized with a rhodium catalyst. The corresponding polymer with a moderate molecular weight was obtained in a high yield. The ester groups of the polymer could be transformed into free carboxy groups by alkaline hydrolysis. Polarimetric, CD, and UV–vis spectroscopy analyses revealed that the polymers took a predominantly one-handed helical structure in solvents. The secondary structures of the polymers could be tuned with heat and solvents.

    13. Cyclic and branched functional polyesters derived from 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl spirobisindane and various dicarboxylic acids (pages 1699–1706)

      Hans R. Kricheldorf and Kerstin Bornhorst

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21938

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      Most polycondensations of 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl spirobisindane with various dicarboxylic acid dichlorides yielded gels. However, one class of dicarboxylic acids yielded soluble cyclic polyesters.

    14. Synthesis and characterization of polyimide containing PEG/PDMS amphiphilic conetworks by hydrosilylation: Correlation between structure and properties (pages 1707–1726)

      M. Srividhya and B. S. R. Reddy

      Version of Record online: 15 MAR 2007 | DOI: 10.1002/pola.21939

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      Highly soluble siloxane systems containing hard imide segments were synthesized using poly(ethylene glycol) units. The systems show high thermal stability with phase separation. The amphiphilic poly(imide siloxane) co-networks were synthesized and were found to exhibit improved thermal and mechanical behavior when compared to the siloxane networks without hard imide segments. They were also found to show phase separated tricomponent networks. [Color version of the adjacent figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    15. Poly(triarylamine): Its synthesis, properties, and blend with polyfluorene for white-light electroluminescence (pages 1727–1736)

      Hung-Yi Lin, Guey-Sheng Liou, Wen-Ya Lee and Wen-Chang Chen

      Version of Record online: 23 MAR 2007 | DOI: 10.1002/pola.21940

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      A new high-molecular-weight poly(triarylamine), poly[di(1-naphthyl)-4-anisylamine], was successfully synthesized by oxidative coupling polymerization from di(1-naphthyl)-4-anisylamine with FeCl3 as an oxidant. It exhibited reversible oxidative redox couples and a maximum peak at 478 nm with a quantum efficiency of 10% in comparison with that of quinine sulfate. Unusual multiple photoluminescence maxima were observed at 546 nm, and this suggested its potential application in white-light-emission devices.

    16. Synthesis and characterization of novel poly(ester carbonate)s based on pentaerythritol (pages 1737–1745)

      Zhigang Xie, Changhai Lu, Xuesi Chen, Li Chen, Yu Wang, Xiuli Hu, Quan Shi and Xiabin Jing

      Version of Record online: 20 MAR 2007 | DOI: 10.1002/pola.21941

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      Novel poly(ester carbonate)s were synthesized by ring-opening polymerization of L-lactide and functionalized carbonate monomer 9-phenyl-2,4,8,10-tetraoxaspiro[5,5]undecan-3-one derived from pentaerythritol using diethyl zinc as an initiator. After removal of the protecting benzylidene groups by hydrogenation with Pd(OH)2/C as catalyst, copolymer poly(L-lactide-co-2,2-dihydroxylmethyl-propylene carbonate) was obtained. The free primary pendant hydroxyl groups on the copolymer prepared are expected to facilitate further functionalization of the copolymer, and this provides possibility for covalent attachment of drugs or other bioactive matters.

    17. Synthesis and characterization of white-light-emitting polyfluorenes containing orange phosphorescent moieties in the side chain (pages 1746–1757)

      Chongyu Mei, Junqiao Ding, Bing Yao, Yanxiang Cheng, Zhiyuan Xie, Yanhou Geng and Lixiang Wang

      Version of Record online: 20 MAR 2007 | DOI: 10.1002/pola.21942

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      White electroluminescence was realized with a polymer consisting of blue fluorescent polyfluorene with orange phosphorescent iridium complex units in side chains. Through the control of the content and emission wavelength of the iridium complex units in the polymer, a white polymer light-emitting diode was constructed with Commission Internationale de L'Eclairage coordinates of (0.46, 0.33) and a maximum luminous efficiency of 4.49 cd/A.

    18. Regioregular poly[3-(4-alkoxyphenyl)thiophene]s (pages 1758–1770)

      Antonio Roviello, Annamaria Buono, Antonio Carella, Giuseppina Roviello, Antonio Cassinese, Mario Barra and Mariano Biasucci

      Version of Record online: 20 MAR 2007 | DOI: 10.1002/pola.21943

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      New regioregular poly[3-(4-alcoxyphenyl)thiophene]s have been prepared by means of an easy synthetic procedure. The results of UV–vis, 13C NMR, and X-ray powder diffraction analysis suggest a high regioregularity degree of the synthesized polymers. A preliminary electrical characterization was performed on one of the synthesized polythiophenes on both undoped and doped (with FeCl3 or iodine) films. As a fact of technological relevance, it is noteworthy that well-structured polymer films were obtained simply via spin coating from chloroform solutions and without the need of further processing, unlike other regioregular polythiophenes reported in the literature.

    19. Synthesis of polymer particles possessing radical initiating sites on the surface by emulsion copolymerization and construction of core–shell structures by a photoinduced atom transfer radical polymerization approach (pages 1771–1777)

      Koji Ishizu, Naoyuki Kobayakawa, Satoshi Takano, Yoko Tokuno and Masaaki Ozawa

      Version of Record online: 20 MAR 2007 | DOI: 10.1002/pola.21944

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      The crosslinked polystyrene particles possessing photofunctional N,N-diethyldithiocarbamate groups on their surface were prepared by free-radical emulsion copolymerization of a mixture of styrene, divinylbenzene and 4-vinylbenzyl N,N-diethyldithiocarbamate initiated by redox system under UV irradiation. In this copolymerization, 4-vinylbenzyl N,N-diethyldithiocarbamate played an important role to form hyperbranched structures. The core–shell particles were synthesized by photoinduced atom transfer radical polymerization approach of methyl methacrylate initiated by crosslinked polystyrene particle macroinitiator.

    20. Living carbocationic copolymerization of isobutylene with styrene (pages 1778–1787)

      Judit E. Puskas, Sam W. P. Chan, Kimberley B. Mcauley, Gabor Kaszas and Sohel Shaikh

      Version of Record online: 20 MAR 2007 | DOI: 10.1002/pola.21945

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      This article investigates the carbocationic copolymerization of isobutylene with styrene, using real-time FTIR spectroscopy combined with traditional gravimetric sampling. By monitoring the individual monomer consumption, FTIR gave unprecedented insight into the reaction. Kelen–Tüdös analysis of the system revealed penultimate effects. Under specific conditions, living polymerizations were found.

    21. Aqueous solution and solid state interactions of lanthanide ions with a methacrylic ester polymer bearing pendant 15-crown-5 moieties (pages 1788–1799)

      F. Rubio, F. García, H. D. Burrows, A. A. C. C. Pais, A. J. M. Valente, M. J. Tapia and J. M. García

      Version of Record online: 20 MAR 2007 | DOI: 10.1002/pola.21946

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      This work describes the interaction between trivalent lanthanide ions and a methacrylic polymer bearing pendant 15-crown-5 moieties, PCR5, in aqueous solution and in the solid state. In aqueous solution a weak interaction between the lanthanides and PCR5 is observed by NMR and by conductivity methods. When the lanthanide ions are adsorbed on PCR5 membranes, Tb(III) lifetime experiments indicate that in solid state the lanthanide(III)-PCR5 interaction is stronger than in solution. SEM shows that the membrane morphology is not much affected by lanthanide adsorption. Support for lanthanide ion–crown interactions comes from ab initio calculations.

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