bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface morphology and amide concentration depth profile of aminolyzed poly(ethylene terephthalate) films
Authors: Avadanei Mihaela , Drobota Mioara , Stoica Iuliana , Rusu Elena , Barboiu Virgil 
Published: October 2010

AbstractSurface of biaxially oriented poly(ethylene terephthalate) films was chemically modified by exposure to ethylenediamine (EDA), triethylenetetramine (TETA), and tetraethylenepentamine (TEPA) for different treatment times. Variable angle attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy was used in conjunction with weight loss measurements, scanning electron microscopy (SEM), and atomic force microscopy to establish the surface modification and to draw the depth profile of the newly created species, with emphasis on amide group. A clear differentiation was found between the effects of the three amines studied: EDA produces the highest amidation degree but, because of its deep penetration into the film, leads to delamination of rather thick layers, TETA reacts at and near surface and develops surface cracks without delamination, and TEPA is the mildest reactant, generating amide groups on the surface without visible deterioration of the sample. It was proved that the amide II absorption band became weaker with increasing analyzed depth, with a pronounced heterogeneity near the surface. SEM micrographs showed the development of cracks onto the surface at longer aminolysis time, which allowed a better understanding of ATR‐FTIR observations. Assuming an exponential decay for the depth profile spectrally obtained, the surface concentration of amide groups and the decay constant were determined for the amines and reaction times used. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Novel poly(ethylene glycol) monomers bearing diverse functional groups
Authors: Mizrahi Dana M. , Omer‐Mizrahi Melany , Goldshtein Jenny , Askinadze Nataly , Margel Shlomo 
Published: October 2010

AbstractPoly(ethylene glycol) (PEG) mono methacrylate ester (MAPEG) has been used, through a variety of reactions, to form several novel monomers, bearing both a polymerizable handle and various functional groups. These new compounds may be conjugated to biomolecules via amine, acid, or thiol moieties or they may form dendrimers via the epoxide. In addition, polymerization of these monomers may result in functionalized nanoparticles and microparticles or coatings, thus altering the acid‐base or electrochemical properties of surfaces and particles. Full synthetic considerations, including interesting intermediates, are reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
A convenient route to PHB macromonomers via anionically controlled moderate‐temperature degradation of PHB
Authors: kawalec Michał , Sobota Michał , Scandola Mariastella , Kowalczuk Marek , Kurcok Piotr 
Published: October 2010

AbstractThe degradation of poly(3‐hydroxybutyrate)s in homo‐ and heterogeneous mixtures with selected salts of organic and mineral acids was investigated. Nonvolatile degradation products, of processes conducted at moderate temperatures (150–170 °C), were analyzed using 1H NMR. Analysis of results revealed a significant decrease in poly([R]‐3‐hydroxybutyrate) (PHB) thermal stability in the presence of acetic acid and carbonic acid salts of alkali metals (Cs, K, Li) as well as a less substantial effect with respect to bivalent metal (Ca, Mg, Zn) salts. This significant decrease in PHB thermal stability in the presence of salts of weak Bronsted‐Lowry acids can be explained in terms of an anionic degradation reaction proceeding via an E1cB mechanism. Furthermore, continuous poly(3‐hydroxybutyrate) controlled degradation was developed by a moderate‐temperature process using carbonic acid salts as “initiators” of anionic degradation. Foamed PHB macromonomers, bearing one crotonate terminal group, were obtainable via a reactive extrusion process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Thiol‐terminated polyisobutylene: Synthesis, characterization, and derivatization
Authors: Magenau Andrew J. D. , Hartlage Todd R. , Storey Robson F. 
Published: October 2010

AbstractThiol‐terminated polyisobutylene (α,ω‐PIB‐SH) was synthesized from thiourea and α,ω‐bromine‐terminated PIB in a three‐step, one‐pot procedure, using a cosolvent system of 1:1 (v:v) heptane:dimethylformamide. The initial alkylisothiouronium salt was produced at 90 °C. Aqueous base hydrolysis at 110 °C resulted in thiolate chain ends, which were re‐acidified to form telechelic PIB‐SH. 1H and 13C NMR confirmed thiol functionality and complete terminal halogen conversion. Thiol‐based “click” reactions were used to demonstrate PIB‐SH utility. Alkyne‐terminated PIB was synthesized by a phosphine‐catalyzed thiol‐ene Michael addition with propargyl acrylate. Reaction of this product with 6‐mercaptohexanol produced tetrahydroxy‐functional PIB by a sequential thiol‐ene/thiol‐yne procedure. 1H NMR confirmed the structures of both products. PIB‐SH was reacted with isocyanates in the presence of base to produce polythiourethanes. A model reaction used phenyl isocyanate in THF with catalytic triethylamine. Similar conditions were used to produce PIB‐based thiourethanes with and without a small‐molecule chain extender. Increased molecular weights and thiol group conversion were observed with GPC and 1H NMR, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis of three new 1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl) pyrrole‐based donor polymers and their bulk heterojunction solar cell applications
Authors: Tamilavan Vellaiappillai , Song Myungkwan , Jin Sung‐Ho , Hyun Myung Ho 
Published: October 2010

AbstractA series of three new 1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole‐based polymers such as poly[1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole] (PTPT), poly[1,4‐(2,5‐bis(octyloxy)phenylene)‐alt‐5,5'‐(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole)] (PPTPT), and poly[2,5‐(3‐octylthiophene)‐alt‐5,5'‐(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole)] (PTTPT) were synthesized and characterized. The new polymers were readily soluble in common organic solvents and the thermogravimetric analysis showed that the three polymers are thermally stable with the 5% degradation temperature >379 °C. The absorption maxima of the polymers were 478, 483, and 485 nm in thin film and the optical band gaps calculated from the onset wavelength of the optical absorption were 2.15, 2.20, and 2.13 eV, respectively. Each of the polymers was investigated as an electron donor blending with PC70BM as an electron acceptor in bulk heterojunction (BHJ) solar cells. BHJ solar cells were fabricated in ITO/PEDOT:PSS/polymer:PC70BM/TiOx/Al configurations. The BHJ solar cell with PPTPT:PC70BM (1:5 wt %) showed the power conversion efficiency (PCE) of 1.35% (Jsc = 7.41 mA/cm2, Voc = 0.56 V, FF = 33%), measured using AM 1.5G solar simulator at 100 mW/cm2 light illumination. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Functionalization of multiwalled carbon nanotubes with polyesters via bergman cyclization and “grafting from” strategy
Authors: Ma Jianguo , Cheng Xin , Ma Xiaowei , Deng Sheng , Hu Aiguo 
Published: October 2010

AbstractIn this work, pristine multiwalled carbon nanotubes (MWNTs) were functionalized by utilizing the free radicals generated through Bergman cyclization of enediyne containing compounds 3. Polyesters were subsequently grafted from the surface of MWNTs through ring‐opening polymerization of ε‐caprolactone or lactide initiated by free hydroxy groups generated after hydrolysis of ester groups. Functionalized MWNTs were characterized with a variety of techniques, including TGA, NMR, IR, UV–vis, TEM, and Raman spectroscopy. After surface modification, MWNTs showed good solubility in common organic solvents and polymer solutions. Fabrication of MWNTs polymer nanocomposites was revealed through electrospinning with polycaprolactone. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
The improvement of electro‐optical properties of polymer‐dispersed liquid crystals using copolymer macroinitiator with different glass transition temperature
Authors: Du Xin , Yan Bin , Yao Jiali , Chen Shu , Li Minke , Wang Yinghan 
Published: October 2010

AbstractIn this article, copolymer macroinitiators prepared with styrene and iso‐octyl acrylate by reversible additional‐fragmental chain transfer polymerization were used to prepare polymer‐dispersed liquid crystals (PDLCs) with methyl acrylate. The electro‐optical properties of the PDLCs were investigated. The results showed that the glass transition temperature (Tg) of the macroinitiator has a great influence on the memory effect of the resulting PDLCs. Low driving voltage and low memory effect PDLCs could easily be obtained with copolymer macroinitiators. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis and characterization of soluble conjugated polymers having pyrene moiety in the main chain
Authors: Chen Hui , Hu Xiao , Ng Siu‐Choon 
Published: October 2010

AbstractThree new alternating conjugated polymers consisting of pyrene and 3‐dodecylthiophene (PPyMT), 4,4′‐didodecyl‐2,2′‐bithiophene (PPyBT), or 9,9‐didodecylfluorene (PPyFlu) moieties have been prepared using Suzuki coupling reaction or Sugimoto approaches. The polymers were readily soluble in common organic solvents and exhibited good thermal stability in nitrogen and air atmospheres. The structures and optical properties of the polymers were characterized by NMR, FTIR, XRD, UV–vis, and fluorescence spectroscopy. PPyMT and PPYBT showed blue‐light emission in solution, whereas PPyFlu performed blue‐light emitting in film state. The polymers exhibited an intermolecular aggregation and structural ordering due to pyrene–pyrene π–π stacking interaction. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Optically active composite nanoparticles with chemical bonds between core and shell
Authors: Luo Xiaofeng , Liu Xiaoqing , Chen Bo , Deng Jianping , Yang Wantai 
Published: October 2010

AbstractA facile methodology was developed to prepare a novel type of core/shell nanoparticles (NPs) with optical activity and with chemical bonds between the cores and shells. The cores were prepared via catalytic emulsion copolymerization of substituted acetylene comonomers in which one monomer contains azo groups in side chains. For preparing the core/shell NPs, the azo groups in the seed particles (i.e., cores) subsequently act as initiators for vinyl monomer to undergo free radical polymerizations, yielding the shells. This situation resulted in chemical bonds between cores and shells. Both the seed emulsion and core/shell nanoparticle emulsion exhibited optical activity, derived from the polyacetylenes adopting helical conformation of predominant handedness. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis and characterization of poly(methylmethacrylate)/silica nanocomposites: Study of the interphase by solid‐state NMR and structure/properties relationships
Authors: Avolio Roberto , Gentile Gennaro , Avella Maurizio , Capitani Donatella , Errico Maria Emanuela 
Published: October 2010

AbstractOrganic/inorganic nanocomposites were synthesized from poly(methylmethacrylate) (PMMA) and properly modified silica nanoparticles by in situ polymerization. Methacryloylpropyltrimethoxysilane was selected as nanoparticle surface modifier because it is characterized by unsaturated end groups available to radical reactions, making possible to suppose their participation in the acrylic monomer polymerization. As a result of the above hypothesized reactions, a phase constituted by polyacrylic chains grafted onto modified silica surface was isolated. 29Si and 13C solid‐state nuclear magnetic resonance experiments permitted to analyze this phase in terms of composition and chain mobility as well as to highlight interaction mechanisms occurring between growing PMMA oligoradicals and functional groups onto silica surface. It was demonstrated that this PMMA grafted onto silica surface acts as an effective coupling agent and assures a good dispersion of nanoparticles as well as a strong nanoparticle/matrix interfacial adhesion. As a result of strong interactions occurring between phases, a significant increase of the glass transition temperature was recorded. Finally, the abrasion resistance of PMMA in the hybrids was significantly improved as a result of a different abrasion propagation mechanism induced by silica particles thus overcoming one of the most serious PMMA drawback. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Fractionated crystallization of α‐ and β‐nucleated polypropylene droplets
Authors: Langhe Deepak S. , Keum Jong K. , Hiltner Anne , Baer Eric 
Published: October 2010

AbstractA layer multiplying coextrusion process was used to produce multilayered polypropylene/polystyrene (PP/PS) films with various nucleating agents. When heated into the melt, the thin PP layers broke up into submicron PP droplets that exhibited fractionated crystallization. If the initial PP layers were 20 nm or less, the resulting droplets exhibited exclusively homogeneous nucleation. If a nucleating agent was added, the systematic departure from homogeneous nucleation provided insight into the nature of the heterogeneous nucleation. In this study, we used thermal analysis, atomic force microscopy (AFM), and wide angle X‐Ray scattering (WAXS) to examine the effect of two nucleating agents. We confirmed with WAXS and AFM that a soluble sorbitol nucleating agent for the PP α‐form operates in three concentration regimes as proposed in a previous study. Morphologically, homogeneous nucleation of the submicron droplets produced a granular texture. The correlation length from small‐angle X‐Ray scattering (SAXS) suggested that the grains contained 1–3 mesophase domains. Drawing on classical nucleation theory, the critical size nucleus of an individual mesophase domain was estimated to be about 2 nm3, which was considerably smaller than the mesophase domain. This pointed to mesophase crystallization that included the processes of nucleation and growth. Additional experiments were performed with nucleating agents for the PP β‐form. However, they were not effective in nucleating crystallization of the droplets, presumably because they were essentially insoluble in PP and the nucleating particles were too large to be accommodated in the PP droplets. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
The role of patient–provider communication for black women making decisions about breast cancer treatment
Authors: Sheppard Vanessa B. , Adams Inez F. , Lamdan Ruth , Taylor Kathryn L. 
Published: October 2010

AbstractObjective: Recent reports suggest that Black breast cancer patients receive adjuvant therapies less often than their White counterparts; however, few studies have examined the self‐reported experiences of Black breast cancer patients making treatment decisions. This study examined cultural beliefs and healthcare factors that impacted Black women's treatment decisions.Methods: In‐depth interviews were conducted with 49 Black women with early stage breast cancer (stages 0‐III). Participants resided in Washington, DC (n = 13), and Philadelphia, Pennsylvania (n = 36). Women's ages ranged from 26 to 85 (m = 53.9). All interviews were transcribed verbatim and then entered into a qualitative software program. Three coders independently read and coded transcripts using this software.Results: The data did not reveal common cultural themes that influenced women's treatment decisions. Spiritual beliefs were important to all participants and did seem to help them cope with and reframe their illness experiences. The patient–provider relationship was the most notable factor that influenced treatment decisions. While most women reported that they were satisfied with their provider relationships, their narratives revealed that many lacked knowledge about their diagnoses and treatment regimens. Those patients who demonstrated a better understanding of their disease and treatments also seemed to adhere to recommendations for adjuvant therapy.Conclusions: Poor communication may impact treatment decision‐making and, ultimately, outcomes. Important next steps will include quantifying Black women's patient–provider interactions and examining how these factors influence adherence behaviors. Ensuring that patients understand their diagnosis and treatment options will also be important for clinical practice. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluating surrogate variables for improving microarray multiple testing inference
Authors: Lunceford Jared K. , Chen Guang , Hu Peter H. , Mehrotra Devan V. 
Published: October 2010

AbstractThe use of surrogate variables has been proposed as a means to capture, for a given observed set of data, sources driving the dependency structure among high‐dimensional sets of features and remove the effects of those sources and their potential negative impact on simultaneous inference. In this article we illustrate the potential effects of latent variables on testing dependence and the resulting impact on multiple inference, we briefly review the method of surrogate variable analysis proposed by Leek and Storey (PNAS 2008; 105:18718–18723), and assess that method via simulations intended to mimic the complexity of feature dependence observed in real‐world microarray data. The method is also assessed via application to a recent Merck microarray data set. Both simulation and case study results indicate that surrogate variable analysis can offer a viable strategy for tackling the multiple testing dependence problem when the features follow a potentially complex correlation structure, yielding improvements in the variability of false positive rates and increases in power. Copyright © 2010 John Wiley & Sons, Ltd.
A control scheme integrating the T chart and TCUSUM chart
Authors: Qu Liang , Wu Zhang , Liu Tien‐I 
Published: October 2010

AbstractThis article proposes an integrated scheme (T&TCUSUM chart) which combines a Shewhart T chart and a TCUSUM chart (a CUSUM‐type T chart) to monitor the time interval T between the occurrences of an event or the time between events. The performance studies show that the T&TCUSUM chart can effectively improve the overall performance over the entire T shift range. On average, it is more effective than the T chart by 26.66% and the TCUSUM chart by 14.12%. Moreover, the T&TCUSUM chart performs more consistently than other charts for the detection of either small or large T shifts, because it has the strength of both the T chart (more sensitive to large shifts) and the TCUSUM chart (more sensitive to small shifts). The implementation of the new chart is almost as easy as the operation of a TCUSUM chart. Copyright © 2010 John Wiley & Sons, Ltd.
On the expected parts per million nonconforming levels obtained from estimated process capability indices
Authors: Ozkaya Banu Yuksel , Testik Murat Caner 
Published: October 2010

AbstractProcess capability indices (PCIs) and parts per million (PPM) nonconforming (NC) levels are widely used in quality improvement programs for quantifying the capability of a process to meet specification requirements. Calculation of PCIs requires knowledge of the process parameters, however, true parameter values are often unknown in practice and therefore estimates obtained from a sample of observations are utilized. On the other hand, as often done in practice, expected PPM NC levels may be evaluated by using a given value of a PCI. However, such estimates of the PPM NC levels might be significantly different from the actual levels due to the additional variability introduced through parameter estimation. In this paper, the effects of estimated PCIs on the PPM NC estimates are quantified. Through evaluating the distributions of PPM NC estimates, it is demonstrated that estimation error is critical and might have significant effects on the PPM NC estimates. Copyright © 2010 John Wiley & Sons, Ltd.
Coordination–insertion copolymerization of polar vinyl monomers by palladium catalysts
Authors: Ito Shingo , Nozaki Kyoko 
Published: October 2010

AbstractRandom incorporation of polar functional groups into polyolefins and polyketones along with the precise control of incorporation ratios and polymer microstructures is one of the most significant challenges in polymer chemistry. For such a purpose, late‐transition‐metal complexes are often employed as a catalyst for the copolymerization of polar vinyl monomers, because of their high functional group compatibility. This acount describes our contribution to the development of coordination–insertion copolymerization of polar vinyl monomers by palladium catalysts. In particular, the use of palladium/phosphine–sulfonate catalysts enables to incorporate various polar vinyl monomers into polyolefins and polyketones. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 315–325; 2010: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.201000032
Production Test Considerations for Mixed‐signal IC with Background Calibration
Authors: Yagi Takuya , Kobayashi Haruo , Tan Yohei , Ito Satoshi , Uemori Satoshi , Takai Nobukazu , Yamaguchi Takahiro J. 
Published: October 2010

AbstractThis paper proposes an improved method of background calibration that reduces the production testing time of mixed‐signal ICs. Production testing time typically consists of ‘calibration convergence time’ and ‘functional testing time’ following calibration convergence. The method of reducing calibration convergence time that is proposed here does not require an extra ADC operation for functional testing after calibration convergence, and can be implemented with a little additional on‐chip test‐support circuitry when testing is performed by an automatic test equipment (ATE). We discuss the application of this method to background calibration of pipelined ADCs, and present simulation results that demonstrate its effectiveness in reducing testing time. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Oscillation Mechanism Analysis of theN‐stage Ring Oscillator ORIGAMI
Authors: Shima Takeshi , Kusaga Takashi 
Published: October 2010

AbstractQuadrature oscillators are effective in applications such as clock‐recovery circuits and complex signal processing. In this paper, the oscillation mechanism of theN‐stage ring oscillator is analyzed experimentally. The analysis is applied to a quadrature oscillator proposed in 2008, called theORIGAMIoscillator. The oscillation mechanism of the ORIGAMI oscillator, in which the wired‐OR configuration is used, is analyzed. To verify the proposed oscillation mechanism, we extend the analysis toN‐stage ring oscillators and describe the characteristics of the proposedN‐stage ring oscillator. The oscillation frequency is also formulated. Analytical results are simulated and evaluated using an HSPICE simulator assuming 0.18 µm CMOS processes. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.