bluuebunny/crossref_metadata_2025_split huggingface dataset:
The condensation kinetics of polyphthalamides. I. Diamines and diacids or dimethylesters
Authors: Malluche Jan , Hellmann Goetz P. , Hewel Manfred , Liedloff Hanns‐Jörg 
Published: September 2007

AbstractSemiaromatic polyamides are high‐performance thermoplastics with a huge potential but also a high price. In this study, the condensation kinetics of aliphatic diamines with aromatic diacids, diesters, and polyesters were investigated, to find ways of producing semiaromatic polyamides at lower costs. The condensation of hexamethylene diamine with phthalic acids and their dimethylesters are discussed in this Part I. The amidation of phthalic acids turned out to proceed like the amidation of adipic acid leading to PA66, only more slowly. The amidation of dimethylphthalates proved to be difficult. It is accompanied by a side reaction of amino alkylation which prevents the growth of long polyamide chains. This side reaction was investigated kinetically in detail, using model compounds that were unable to polymerize. The aim was to provide a basis for attempts to amidate polyesters, in particular, PET, which will be reported in Part II. POLYM. ENG. SCI., 47:1589–1599, 2007. © 2007 Society of Plastics Engineers
Condensation kinetics of polyphthalamides. II. Polyesters and diamines
Authors: Hellmann Edith , Malluche Jan , Hellmann Goetz Peter 
Published: September 2007

AbstractPolyphthalamides are distinguished by outstanding properties. Only their price keeps them from replacing PA66 in many applications, in particular, in automobiles. This article deals with a simple, economically attractive process of upcycling postconsumer polyethylene terephthalate (PET) waste to polyphthalamides. Basic studies on the amidation of acids and esters were described in Part I. The amidation of esters is accompanied by a side reaction of amine alkylation, which, in the case of polyesters, leads to branching and crosslinking. But the crosslinking can be avoided in mixtures with excessive diamine. Therefore, a heterogeneous amidation process was developed in which solid PET granules are simultaneously dissolved in and amidated by a liquid diamine. As long as the PET‐diamine system is heterogeneous, it reacts under amino excess conditions. Later, when all PET is dissolved, it comes back to stoichiometric conditions again, so long‐chained polyamides can be obtained. In terms of molar mass and viscosity, this amidation of solid PET proceeds very similarly to the amidation of terephthalic acid (TPA), which is so far the common route towards polyphthalamides. PET waste could replace TPA. POLYM. ENG. SCI., 47:1600–1609, 2007. © 2007 Society of Plastics Engineers
The effect of multiwall carbon nanotube on the crystallization, morphology, and rheological properties of nylon1010 nanocomposites
Authors: Wang Biao , Sun Guangping , He Xiaofeng , Liu Jingjiang 
Published: September 2007

AbstractNanocomposites based on poly(iminosebacoyl iminodecamethylene) (PA1010) and multiwall carbon nanotubes (MWNTs) were successfully prepared by melt blending technique. environmental scanning electron microscope micrographs of the fracture surfaces showed that not only is there an evenly dispersion of MWNTs throughout the PA1010 matrix but also a strongly interfacial adhesion with the matrix. The combined effect of more defects on MWNTs and low temperature buckling fracture is mainly responsible for the broken tubes. Differential scanning calorimeter results showed that the MWNTs acted as a nucleation agent and increased the crystallization rate and decreased crystallite size. In the linear region, rheological measurements showed a distinct change in the frequency dependence of storage modulus, loss modulus, and complex viscosity particularly at low frequencies. We conclude that the rheological percolation threshold might occur when the content of MWNTs is over 2 wt% in the composites. POLYM. ENG. SCI., 47:1610–1620, 2007. © 2007 Society of Plastics Engineers
Rapid sensing of trace ionic substances with the novel porous monolith type ion exchanger
Authors: Aoki Hidemitsu , Miyano Kazuki , Yano Daisaku , Sano Kazuhiko , Yamanaka Koji , Kimura Chiharu , Sugino Takashi 
Published: September 2007

AbstractBiological and chemical sensor with a rapid response in microlevel test is required for health and environmental monitor. A novel sensing due to porous ion exchanger with three‐dimensional acceptor has been first attempted to develop a high‐performance sensor. This porous monolith type ion exchanger has an open‐cellular monolith structure with 5–50‐μm diameter pores. The trace amount of inorganic ions dissolved in aqueous solutions can be quantitatively determined with the impedance given by the monolith, which attracts and adsorbs the ions rapidly. We have succeeded in detecting ions with a concentration as low as 10−7 mol. The porous ion exchanger has a potentiality as a high‐performance device for biological and chemical sensing. POLYM. ENG. SCI., 47:1666–1670, 2007. © 2007 Society of Plastics Engineers
Sulphonic acids doped poly(N‐ethyl aniline): A material for humidity sensing application
Authors: Kulkarni Milind V. , Viswanath Annamraju Kasi 
Published: September 2007

AbstractSubstituted polyaniline, poly(N‐ethyl aniline) (PNEA), doped with camphor sulphonic acid (CSA) and p‐toluene sulphonic acid (p‐TSA), was synthesized by single‐step chemical polymerization method using ammonium persulphate as an oxidizing agent. This is a single‐step polymerization process to synthesize directly the conducting emeraldine salt phase of the polymer using CSA and p‐toluene sulphonic acid as dopants. The synthesized polymers were characterized by UV–vis and FTIR spectroscopy, scanning electron microscopy, TGA/SDTA, DSC, and conductivity measurements. This single‐step chemical synthesis method offers a polymer having very good physicochemical properties with good electrical conductivity. High temperature conductivity measurements show “thermal activated behavior.” The change in resistance with respect to % relative humidity (% RH) is observed, when pressed pellets of the polymer were exposed to the broad range of humidity (ranging between 20 and 100% RH). POLYM. ENG. SCI., 47:1621–1629, 2007. © 2007 Society of Plastics Engineers
Dynamic and viscoelastic behavior of natural rubber/layered silicate nanocomposites obtained by melt blending
Authors: Ramorino G. , Bignotti F. , Conzatti L. , Ricco T. 
Published: September 2007

AbstractVulcanized natural rubber/layered silicate (montmorillonite) nanocomposites prepared by melt blending with different contents of organoclay (0, 5, 10, 20 wt%) were investigated. The morphological characteristics of the materials were studied by transmission electron microscopy (TEM), wide angle X‐ray diffraction, and dynamic mechanical thermal analysis (DMTA). X‐ray spectra evidence some intercalation of the clay, while TEM results show a good dispersion of the clay and the occurrence of partial delamination. DMTA analysis with varying temperature shows that the peak of the loss modulus broadens by increasing the clay content within the material, though the peak temperature is scarcely affected. Mechanical reinforcement induced by the presence of the clay is evidenced by static tensile tests. At every clay content explored, dynamic experiments show a nonlinear behavior (Payne effect), which strongly increases with the amount of clay incorporated and is considerably more pronounced than in natural rubber filled with comparable amounts of conventional fillers. The viscoelastic behavior of the materials is investigated by recovery tests of low amplitude storage modulus, carried out after the application of a large strain perturbation, and by stress relaxation experiments. POLYM. ENG. SCI., 47:1650–1657, 2007. © 2007 Society of Plastics Engineers
Numerical investigation and visualization of polymer behavior within a capillary die
Authors: Beard M.A. , Tabor G.R. , Ritchie S.J.K. , Evans K.E. 
Published: September 2007

AbstractNumerical analysis of the flow regime within a capillary rheometer has been studied. The vector‐based Remmelgas‐Harrison‐Leal (RHL), analogous to reptation‐based polymer models, has been used to model the polymer dynamics. A series of computational methods for visualizing the flow characteristics of the whole region of the capillary rheometer are made including the area directly in front of the piston. Model predictions provide qualitative analysis of pressure drops observed at the entrance of the die, necessitating the use of the Bagley ends correction in practical rheology measurements. The results of the numerical code help reveal the complex flow kinematics that are involved in the entrance region to the capillary die as well as the barrel region in front of the rheometer piston. POLYM. ENG. SCI., 47:1688–1694, 2007. © 2007 Society of Plastics Engineers
Toughening of epoxy resin with amine functional aniline acetaldehyde condensate
Authors: Maity T. , Samanta B.C. , Dalai S. , Banthia A.K. 
Published: September 2007

AbstractThe diglycidyl ether of bisphenol‐A (DGEBA) resin was modified with amine functional aniline acetaldehyde condensate (AFAAC) and cured with an ambient temperature curing agent triethylene tetramine. The resulting networks displayed significantly improved fracture toughness. The AFAAC was synthesized by the condensation reaction of aniline and acetaldehyde in the acid medium (pH 4) and characterized by FTIR and NMR spectroscopy, elemental analysis, viscosity measurements, and mole of primary and secondary amine analysis. The DGEBA and AFAAC were molecularly miscible but developed a two‐phase microstructure upon network formation. Epoxy/AFAAC compositions were systematically varied to study the effect of AFAAC concentration on the impact, adhesive, tensile, and flexural properties of modified networks. The dynamic mechanical analysis and scanning electron microscopy studies showed two phase morphology in the cured networks, where AFAAC particles were dispersed. The AFAAC modified epoxy network was thermally stable up to around 280°C. POLYM. ENG. SCI., 47:1695–1702, 2007. © 2007 Society of Plastics Engineers
Elastomer swelling in mixed associative solvents
Authors: Westbrook P.A. , French R.N. 
Published: September 2007

AbstractThe applicability of a linear partition model, which correlates elastomer swell in equilibrium with mixed solvents, is extended to include solutions that exhibit significant self‐association and also cross‐association among the constituents. Combined with Chemical Theory to characterize the behavior of associative solutions, the linear partition model conveniently accounts for both positive and negative excess absorption by elastomers over the entire solution composition. The method requires thermodynamic activity data for each component as a function of concentration, a rational model for the nature of chemical association and one observation of elastomer swell for each chemical species in solution. Prior knowledge of the chemical structure of the elastomer is not required. POLYM. ENG. SCI., 47:1554–1568, 2007. © 2007 Society of Plastics Engineers
Reinforcement of epoxy networks with sulfur‐ and carbon‐based molecular fortifiers
Authors: Lesser Alan J. , Calzia Kevin , Junk Matthais 
Published: September 2007

AbstractEarlier research with phosphorus‐based molecular fortifiers showed a range of improvements in physical, thermal, and mechanical properties. This contribution introduces sulfur‐ and carbon‐based molecules into a model epoxy network for comparison. Similar improvements inrheological, physical, and select mechanical propertiesare found between the phosphorus and sulfur‐ and carbon‐based fortifiers. Thermal properties are not enhanced with the sulfur and carbon fortifiers. Two of the sulfur compounds phase separate upon cure of the epoxy network and show unique behavior. In addition, infrared spectroscopy is performed to identify possible mechanisms of reinforcement. POLYM. ENG. SCI., 47:1569–1575, 2007. © 2007 Society of Plastics Engineers
Screening flame retardants for plastics using microscale combustion calorimetry
Authors: Lyon Richard E. , Walters R.N. , Stoliarov S.I. 
Published: September 2007

AbstractMicroscale combustion calorimetry (MCC) was evaluated as a screening test for efficacy of flame‐retardant additives in polymers. The MCC method separately reproduces the gas and condensed phase processes of flaming combustion in a nonflaming laboratory test and forces them to completion to obtain intrinsic/material combustion properties. At flame extinction, these MCC combustion properties are comparable in magnitude and effect to the extrinsic factors (sample size and orientation), physical behavior (dripping, swelling), and chemical processes (flame inhibition, charring) associated with flame retardancy. Consequently, MCC properties by themselves cannot correlate flame resistance of plastics over a broad range of flame‐retardant chemical composition. POLYM. ENG. SCI., 47:1501–1510, 2007. © 2007 Society of Plastics Engineers
How is it possible to produce highly oriented yarns of electrospun fibers?
Authors: Moon SungCheal , Farris Richard J. 
Published: September 2007

AbstractElectrospinning of polymeric nanofibers onto a stationary grounded target produces a nonwoven mat‐like material. Using a rapidly rotating grounded target in the form of a wheel or belt, it is possible to produce significant lengths of highly oriented yarns of electrospun filaments. This observation is difficult to explain when one compares the calculated velocity of an electrospun monofilament with the surface velocity of the grounded target. This study was undertaken to attempt to answer this question. Are the calculated fiber velocities correct? Is the collected electrospun filament really a monofilament? Does the electrospun filament split into multiple filaments or do fibers loop in an oriented manner on the collection wheel? POLYM. ENG. SCI., 47:1530–1535, 2007. © 2007 Society of Plastics Engineers
Preparation of nanoparticles of double‐hydrophilic PEO‐PHEMA block copolymers by AGET ATRP in inverse miniemulsion
Authors: Oh, Jung Kwon , Dong Hongchen , Zhang Rui , Matyjaszewski Krzysztof , Schlaad Helmut 
Published: September 2007

AbstractAtom transfer radical polymerization with activators generated by electron transfer initiating/catalytic system (AGET ATRP) of 2‐hydroxyethyl methacrylate (HEMA) was carried out in inverse miniemulsion. Water‐soluble ascorbic acid as a reducing agent and mono‐ and difunctional poly(ethylene oxide)‐based bromoisobutyrate (PEO‐Br) as a macroinitiator were used in the presence of CuBr2/tris[(2‐pyridyl)methyl]amine (TPMA) and CuCl2/TPMA complexes. The use of poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide) as a polymer surfactant resulted in the formation of stable HEMA cyclohexane inverse dispersion and PHEMA colloidal particles. All polymerizations were well‐controlled, allowing for the preparation of well‐defined PEO‐PHEMA and PHEMA‐PEO‐PHEMA block copolymers with relatively high molecular weight (DP > 200) and narrow molecular weight distribution (Mw/Mn < 1.3). These block copolymers self‐assembled to form micellar nanoparticles being 10–20 nm in diameter with uniform size distribution, and aggregation number of ∼10 confirmed by atomic force microscopy and transmission electron microscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4764–4772, 2007
Random fluorene copolymers with on‐chain quinoxaline acceptor units
Authors: Tsami Argiri , Yang Xiao‐Hui , Galbrecht Frank , Farrell Tony , Li Hongbo , Adamczyk Sylwia , Heiderhoff Ralf , Balk Ludwig Josef , Neher Dieter , Holder Elisabeth 
Published: September 2007

AbstractTwo series of novel random polyfluorene copolymers containing quinoxaline units were prepared by stressing the coupling according to Yamamoto. The first series contains 2,3‐bis‐(4′‐tert‐butyl‐biphenyl‐4‐yl)benzo[g]quinoxaline and the second series 2,3‐bis‐(4′‐tert‐butyl‐biphenyl‐4‐yl)quinoxaline as energy accepting unit. The copolymers were identified by gel permeation chromatography, infrared spectroscopy, and nuclear magnetic resonance spectroscopy. Thermal properties were analyzed by thermal gravimetric analysis and differential scanning calorimetry revealing amorphous copolymers that are stable up to 430 °C. The morphology was investigated using atomic force microscopy. The optical properties in solutions and thin films were analyzed. Furthermore, the thin film electro‐optical properties were determined in monolayer polymer light‐emitting devices. Single layer devices were built with efficiencies ranging from 0.15 to 2.0 cd/A. For the random copolymers with 5 mol % benzo[g]quinoxazoline in the polyfluorene backbone some threefold efficiency enhancement from 1.1 to 3.0 cd/A was achieved by utilizing an ultra thin interlayer of poly(9,9‐di‐n‐octylfluorene‐2,7‐diyl)‐alt‐[1,4‐phenylene‐(4‐sec‐butylphenylimino)‐1,4‐phenylene] between PEDOT:PSS and the emissive random copolymer layer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4773–4785, 2007
Docking with PIPER and refinement with SDU in rounds 6–11 of CAPRI
Authors: Shen Yang , Brenke Ryan , Kozakov Dima , Comeau Stephen R. , Beglov Dmitri , Vajda Sandor 
Published: September 2007

AbstractOur approach to protein–protein docking includes three main steps. First we run PIPER, a new rigid body docking program. PIPER is based on the Fast Fourier Transform (FFT) correlation approach that has been extended to use pairwise interactions potentials, thereby substantially increasing the number of near‐native structures generated. The interaction potential is also new, based on the DARS (Decoys As the Reference State) principle. In the second step, the 1000 best energy conformations are clustered, and the 30 largest clusters are retained for refinement. Third, the conformations are refined by a new medium‐range optimization method SDU (Semi‐Definite programming based Underestimation). SDU has been developed to locate global minima within regions of the conformational space in which the energy function is funnel‐like. The method constructs a convex quadratic underestimator function based on a set of local energy minima, and uses this function to guide future sampling. The combined method performed reliably without the direct use of biological information in most CAPRI problems that did not require homology modeling, providing acceptable predictions for targets 21, and medium quality predictions for targets 25 and 26. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Industrial Statistics: Quality Management, Application and Development
Authors: Tyssedal John 
Published: September 2007

AbstractThe above Special Issue editorial (DOI: 10.1002/qre.880) states the incorrect DOI number for Gerry Hahn's article. The correct number is DOI: 10.1002/qre.863. Also omitted from this editorial is the DOI number of the Barone et al. paper, which is DOI: 10.1002/qre.866. These errors will be corrected prior to print publication.
Guaranteed cost control of T–S fuzzy systems with input delay
Authors: Chen Bing , Lin Chong , Liu Xiaoping , Tong Shaocheng 
Published: September 2007

AbstractThis paper is concerned with the problem of guaranteed cost control for Takagi–Sugeno (T–S) fuzzy systems with time‐varying input delay. The input delay is of interval type, and no restriction is imposed on the derivative of the time delay. Based on free‐weighting matrix method, new delay‐dependent sufficient conditions for the existence of a fuzzy guaranteed cost controller are provided by means of linear matrix inequalities. Some examples are used to illustrate the effectiveness of the proposed method. Copyright © 2007 John Wiley & Sons, Ltd.
Robust delay‐dependent sliding mode control for uncertain time‐delay systems
Authors: Xia Yuanqing , Liu Guo‐Ping , Shi Peng , Chen Jie , Rees David 
Published: September 2007

AbstractIn this paper, the problem of robust sliding mode control for a class of linear continuous time‐delay systems is studied. The parametric uncertainty considered is a modelling error type of mismatch appearing in the state. A delay‐dependent sufficient condition for the existence of linear sliding surfaces is developed in terms of linear matrix inequality, based on which the corresponding reaching motion controller is designed. A numerical example is given to show the potential of the proposed techniques. Copyright © 2007 John Wiley & Sons, Ltd.
Robust adaptive output‐feedback control for nonlinear systems with output unmodeled dynamics
Authors: Wu Zhaojing , Xie Xuejun , Shi Peng 
Published: September 2007

AbstractIn this paper, for a class of uncertain nonlinear systems in the presence of inverse dynamics, output unmodeled dynamics and nonlinear uncertainties, a robust adaptive output‐feedback controller design is proposed by combining small‐gain theorem, changing supply function techniques with backstepping methods. It is shown that all the signals of the closed‐loop system are uniformly bounded in biased case, and the output can be regulated to a small neighborhood of the origin in unbiased case. Furthermore, under some additional assumptions, an asymptotical result is obtained. Copyright © 2007 John Wiley & Sons, Ltd.
Optimal phase I dose‐escalation trial designs in oncology—A simulation study
Authors: Gerke Oke , Siedentop Harald 
Published: September 2007

AbstractIn phase I oncology trials conducted over the past few decades, the maximum tolerated dose (MTD) has usually been estimated by the traditional escalation rule (TER), which traces back to 1973. In the meantime, new methods have been proposed which hope to estimate the true MTD more precisely than the TER while using less patients. In this simulation study, TER is compared with the accelerated titration dose design (ATD), two up‐and‐down designs (biased coin design, r‐in‐a‐row (RIAR)), the maximum likelihood version of the continual reassessment method (CRML), and a Bayesian method that is implemented in the software Bayesian ADEPT (assisted decision‐making in early phase trials). Each design was applied to 50 000 simulated studies. The designs were then compared for accuracy in detecting the true MTD (which is known here), while taking into account the average number of patients and toxicities per run. In terms of accuracy, ADEPT outperformed the
other methods in the scenario with medium toxicity and was close to the best methods in the low and high toxic scenarios. The average number of patients needed per run was the lowest for TER in the scenario with low toxicity and for ADEPT in the remaining scenarios. The longer the escalation path to the target region of the MTD, the more the difference in the average number of patients per run pronounced between TER and ADEPT. TER induced least toxicities in all scenarios. ADEPT turned out to be quick and accurate in determining the MTD, while TER was the safest but least accurate method. CRML was as accurate as TER, and the up‐and‐down designs did not excel. Bayesian ADEPT is considered a valuable tool for the conduct of phase I dose‐escalation trials in oncology, but careful preparation is indispensable before its practical use. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing non‐inferiority of a new treatment in a three‐arm trial in the presence of heteroscedasticity
Authors: Hasler Mario , Vonk Richardus , Hothorn Ludwig A. 
Published: September 2007

AbstractIn this paper, we describe an adjusted method to facilitate non‐inferiority tests in a three‐arm design. While the methodology is readily available in the situation of homogeneous group variances, the adjusted method will also maintain the α‐level in the presence of heteroscedasticity. We propose explicit criteria for an optimal allocation. Depending on the pattern of heterogeneity, remarkably unbalanced designs are power optimal. We will apply the method to a randomized clinical trial and a toxicological experiment. Copyright © 2007 John Wiley & Sons, Ltd.