bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrids of hybrids: nano‐scale combinations of polyphosphazenes with other materials
Authors: Allcock Harry R. 
Published: March 2010

AbstractAlthough more than 700 different polyphosphazenes are known, with a wide range of physical and chemical properties, a further expansion of materials properties can be accomplished by combining these macromolecules with other materials such as organic polymers, ceramics or semiconductors. These combinations lead to uses in the fields of biomedicine, energy generation and energy storage, and the formation of nano‐particles such as micelles. This article is a review of recent developments in the author's laboratory to combine polyphosphazenes with other materials in order to generate new combinations of useful properties. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and characterization of poly(n‐undecyl isocyanate)/polyaniline polyblend
Authors: Li Yu‐Jen , Ho Ko‐Shan , Lo Wan‐Ting , Yang Shin‐Shiao , Chao Liang , Chang Yu‐Chen , Han Yu‐Kai , Hsieh Tar‐Hwa , Huang Ying‐Jie 
Published: March 2010

AbstractPoly(n‐undecyl isocyanate) (PUDIC)/n‐dodecylbenzenesulfonic acid (DBSA)‐doped polyaniline (PANIDBSA) polyblend was prepared and the effect of the H‐bonding between these two polymers on the compatibility, conjugation chain length of PANIDBSA, and helixity of PUDIC in the polyblend system were studied. The monomer and polymer were characterized by NMR spectra and the polyblend was analyzed by FTIR, UV–vis spectra, and wide‐angle X‐ray diffraction. It was found when the blend composition of the PUDIC was higher than 10%, the WAXD patterns demonstrated lower angle shifting for the peaks at around 2θ = 2–2.5°, referring to the distance between the layers of the layered structure of PANIDBSA crystalline with increasing PUDIC, indicating the expansion of the layered structure of PANIDBSA. The FTIR spectra illustrated the presence of an absorption peak at 1700 cm−1 shift to higher wave number with PUDIC due to its H‐bonding with PANIDBSA. The UV–vis spectra of PANIDBSA described a blue‐shift of the λmax with PUDIC, indicating that the presence of PUDIC in the polyblend system can interrupt and decrease the conjugation chain length of PANIDBSA. The optical activity of the helical PUDIC decreased notably with the presence of PANIDBSA, resulting from the reversed helical effect (de‐nature) of H‐bonding. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and gas permeation properties of a single layer PDMS membrane
Authors: Sadrzadeh Mohtada , Shahidi Kazem , Mohammadi Toraj 
Published: March 2010

AbstractIn this work, a new polydimethylsiloxane (PDMS) membrane was synthesized and its sorption, diffusion, and permeation properties were investigated using H2, N2, O2, CH4, CO2, and C3H8 as a function of pressure at 35°C. PDMS, as a rubbery membrane, was confirmed to be more permeable to more condensable gases such as C3H8. The synthesized PDMS membrane showed much better gas permeation performance than others reported in the literature. Based on the sorption data of this study and other researchers' works, some valuable parameters such as Flory‐Huggins (FH) interaction parameters, χ, etc., were calculated and discussed. The concentration‐averaged FH interaction parameters of H2, N2, O2, CH4, CO2, and C3H8 in the synthesized PDMS membrane were estimated to be 2.196, 0.678, 0.165, 0.139, 0.418, and 0.247, respectively. Chemical similarity of O2, CH4, and C3H8 with backbone structure of PDMS led to lower χ values or more favorable interactions with polymer matrix, particularly for CH4. Regular solution theory was applied to verify correctness of evaluated interaction parameters. Local effective diffusion coefficient of C3H8 and CO2 increased with increasing penetrant concentration, which indicated the plasticization effect of these gases over the range of penetrant concentration studied. According to high C3H8/gas ideal selectivity values, the synthesized PDMS membrane is recommended as an efficient membrane for the separation of organic vapors from noncondensable gases. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Some comparative aspects of particle formation and rate of reaction in emulsion polymerization of vinyl acetate and butyl acrylate
Authors: Jahanzad Fatemeh 
Published: March 2010

AbstractThe comparative study of monomers, in terms of particle formation and rate of polymerization, facilitates the interpretation of the results from the corresponding copolymerization runs and can be considered as a preliminary step toward formulation of copolymerization reactions. Batch emulsion homopolymerization of vinyl acetate (VA) and butyl acrylate (BA), as model monomers with a wide water solubility disparity, were carried out to investigate the effects of variations in the monomer concentration, electrolyte concentration, reaction volume, and surfactant type on the kinetics of polymerization. With sodium lauryl sulfate as surfactant, VA emulsion polymerization produced more particles than BA at a lower monomer concentration, but fewer particles at a higher monomer concentration. At a lower VA concentration, a depressed growth for newly formed particles during interval III contributed to the formation of a large number of particles. The application of aerosol MA and OT surfactants improved the stability of polyvinyl acetate (PVA) particles so that a larger number of polymer particles was obtained for VA, in comparison with BA. BA emulsion polymerization showed little sensitivity to electrolyte concentrations and reaction volumes within the range studied. The colloidal stability of PVA particles was found to be quite sensitive toward the aforementioned variables. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
High‐strength biodegradable poly(vinyl alcohol)/fly ash composite films
Authors: Nath Dilip Chandra Deb , Bandyopadhyay Sri , Boughton Philip , Yu Aibing , Blackburn Darryl , White Chris 
Published: March 2010

AbstractWe prepared biodegradable composite films of poly(vinyl alcohol) (PVA) and fly ash (FA) spanning 5, 10, 15, 20, and 25 wt % concentrations by casting aqueous solutions. The tensile strengths of the composite films were increased proportionally via the addition of FA. The strength of the film was enhanced by 193% with 20% FA compared to the neat PVA control. Further addition of FA deviated from the linear trend. The moduli of the composites also increased proportionally with FA addition to 212% at 20 wt % FA addition compared to the control. The percentage strain at break exponentially decreased with the addition of FA. In the dynamic mechanical behavior, the storage and loss moduli both increased with FA content. The tan δ peaks corresponding to the glass‐transition temperature shifted 5–10°C higher above the control sample (73°C). This shift was attributed to a reduction in the mobility of PVA segments because they were anchored by the FA surface. The reductions in mobility manifested in strong interfacial interactions were indicative of hydrogen bonding. Broadening and reduction in the intensities of the stretching and bending peaks of OH, CH and CO of PVA in the Fourier transform infrared spectra were observed. This suggested that hydrogen bonding was active between the functional groups in the FA and PVA chains. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
New copper phthalocyanine oligomers for high dielectric constant polymer films
Authors: Saha Rituparna , Mandal Braja K. 
Published: March 2010

AbstractWe report here the synthesis of two new oligomeric copper phthalocyanine (CuPc) derivatives by esterification of the corresponding carboxylic acids with tri(ethylene glycol) monomethyl ether. The solubility of these derivatives in N,N′‐dimethylformamide (DMF) enabled us to perform dielectric studies with poly(vinylidene fluoride‐trifluoroethylene) P(VDF‐TrFE), acting as the host polymer matrix. The highest room temperature dielectric constant achieved is 94 at 100 Hz, compared with 12 for the base polymer host matrix. Thermogravimetric analyzes of the polymer films showed that they are thermostable at 100°C for a long period of time. Scanning electron microscopy (SEM) images of the films have also been analyzed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of acryloyloxy guar gum
Authors: Shenoy Mohan A. , D'Melo Dawid John 
Published: March 2010

AbstractGuar gum is a galactomannan commonly used as a viscosity modifier in the food, pharmaceutical, and cosmetics industry. The aim of this study was to synthesize acryloyloxy guar gum via a Schotten‐Bauman reaction in aqueous media. The reaction products were characterized using FTIR, C13‐NMR, wide angle X‐ray diffraction techniques to ascertain the effect of acrylation on the structure of guar gum. The acrylation of guar gum was found to be limited to the primary hydroxyl groups on the guar gum molecule. The maximum degree of substitution (DS) was found to be 0.56, which was observed after 3 h of reaction. Since the reaction was carried out in an aqueous medium after 3 h of reaction the DS of the derivatised guar gum was found to decrease, because of hydrolysis of the formed ester linkages. The ester content and intrinsic viscosity of the derivatised guar gums were also evaluated. Thermal analysis showed that a higher DS resulted in products with lower thermal stability and there was no evidence of reaction via the acrylate groups on heating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Mechanical properties and sliding wear behavior of potassium titanate whiskers‐reinforced poly(ether ether ketone) composites under water‐lubricated condition
Authors: Xie Guang‐You , Zhong Ying‐Jie , Sui Guo‐Xin , Yang Rui 
Published: March 2010

AbstractPolyetheretherketone (PEEK) composites reinforced with potassium titanate whiskers (PTW) were compounded using a twin‐screw extruder followed by injection molding. The effects of PTW on the mechanical properties, crystallization performances and wear behaviors of PEEK under water lubrication have been investigated. It was denoted that the yield strength, Young's modulus, and microhardness of the composites increased with increasing whisker content, but the elongation at break and the impact strength showed decreasing trend. It was revealed that the inclusion of PTW could effectively reduce the friction coefficient and enhance the wear resistance of the PEEK. The DSC tests showed that the crystallinity of the composite slightly decreased with the addition of PTW, which might imply that the crystallinity of PEEK was not the dominant factor that influenced the wear properties of the composites. The enhancement on the wear resistance was attributed to the reinforced effect of PTW on PEEK. The wear mechanism changed from fatigue wear into mild abrasive wear when the PTW was added into PEEK. The lowest wear rate 9.3 × 10−8 mm3/Nm was achieved at 10 wt % PTW content. However, excessive whiskers would cause severe abrasive wear to the composite. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of crosslinked phenolic‐typed beads by dispersion polycondensation of 2‐phenoxyethanol with formaldehyde
Authors: Ji Chunnuan , Shi Jingxi , Sun Changmei , Qu Rongjun , Wang Chunhua , Sun Yanzhi 
Published: March 2010

AbstractA novel dispersion polymerization of 2‐phenoxyethanol (PE) with formaldehyde for the preparation of crosslinked phenolic‐typed beads (CPBs) is reported. Monodisperse CPBs with particle sizes in the range 400–700 μm were obtained. The dispersion polymerization of PE with formaldehyde was conducted with hydroxyethyl cellulose, concentrated sulfuric acid, and formic acid as a stabilizer, catalyst, and solvent, respectively. The effects of reaction variables, including the polymerization temperature, agitation rate, molar ratio of formaldehyde to 2‐phenoxyethanol (F/P), stabilizer concentration, and amount of the catalyst on the particle size, particle size distribution, and morphology, were investigated. Particularly, CPBs of a size 604 μm and a narrow particle size distribution (polydispersity index = 1.193) were prepared under the following conditions: polymerization temperature = 60°C, agitation rate = 700 rpm, stabilizer concentration = 2.5%, F/P = 3 : 1, and amount of catalyst = 8 mL. The resulting CPBs were characterized by scanning electron microscopy and laser particle analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of poly[N′‐(2‐cyanoacetyl)acrylohydrazide] and its copolymers with styrene and N‐phenylacrylamide: Characterization, complexation, thermal stability, swelling, and morphology
Authors: A. Elassar Abdel‐Zaher , El‐Sayed Ahmed E. M. , Ahmed Fared S. 
Published: March 2010

AbstractN′‐(2‐cyanoacetyl)acrylohydrazide (CAH) was obtained with the treatment of 2‐cyanoacetohydrazide with acryloyl chloride in acetonitrile. The obtained acrlyoyl derivative was transferred to the corresponding polymer, poly[N′‐(2‐cyanoacetyl)acrylohydrazide] (PCAH), through treatment with 2,2′‐azobisisobutyronitrile at 75°C. Copolymers with styrene or N‐phenyl acrylamide monomers were synthesized with different ratios. The structures of these polymers were characterized with elemental analysis and spectral data. The morphology, metal uptake, and ion selectivity of the polymers were studied. In addition, the swelling behavior of the polymer and metallopoymer complexes at different times of drying was also investigated. Thermogravimetric analysis of the polymer and polymer complexes under air reflected that PCAH–Pb was the most stable, followed by PCAH, PCAH–Hg, PCAH–Cu, PCAH–Ni, and PCAH–Co. A similar stability with little difference was reported under nitrogen. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Properties of copper phthalocyanine blue encapsulated with a copolymer of styrene and maleic acid
Authors: Fu Shaohai , Ding Lei , Xu Changhai , Wang Chunxia 
Published: March 2010

AbstractCopper phthalocyanine blue was encapsulated with a copolymer of styrene and maleic acid (PSMA) via a phase‐separation technique, and a PSMA‐encapsulated pigment dispersion was prepared. The effects of the additive on the stability of the dispersion were studied. Scanning electron microscopy photographs revealed that the particles in the PSMA‐encapsulated pigment dispersion were more uniform than those in a PSMA‐dispersed pigment dispersion. X‐ray photoelectron spectroscopy provided evidence that the PSMA‐encapsulated pigment acquired abundant carboxylic groups that could improve its wettability to water. Moreover, the results also indicated that the PSMA‐encapsulated pigment dispersion had improved color strength, its stability could be greatly influenced by the pH value and ion strength, and its apparent viscosity changed little with an increase in the shear rate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rheological modeling of fracture in plug‐assisted vacuum thermoforming
Authors: Hosseini H. , Berdyshev B. V. , Mehrabani‐Zeinabad A. 
Published: March 2010

AbstractThe fracture of polymeric sheets is one of the practical problems occurring during plug‐assisted vacuum thermoforming. This defect can occur during both the plug‐assist and vacuum‐forming stages. This article focuses on two issues: (1) the origins of fracture creation and (2) the determination of the process parameters needed for removal of the defect. The results of our work not only lead to an understanding of the cause of this problem but also enable us to calculate the parameters that affect the fracture of polymeric sheets during plug‐assisted vacuum thermoforming. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of nanozirconia on the thermal stability of poly(methyl methacrylate) prepared by in situ bulk polymerization
Authors: Wang Xinlong , Wu Lianghu , Li Jin 
Published: March 2010

AbstractNanozirconia (nano‐ZrO2) was prepared by the sol–gel method and incorporated into poly(methyl methacrylate) (PMMA) by the in situ bulk polymerization of methyl methacrylate. The structure of the nano‐ZrO2 was confirmed by X‐ray diffraction (XRD), transmission electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The structure of the nano‐ZrO2 nanocomposites were studied by differential scanning calorimetry, FTIR spectroscopy, XRD, and scanning electron microscopy, and the results show that there were interactions between the nanoparticles and the polymer. The influence of the nano‐ZrO2 on the thermal stability of PMMA was investigated by thermogravimetric analysis (TGA). The results indicate that nano‐ZrO2 enhanced the thermal stability of the PMMA/nano‐ZrO2 nanocomposites. The effects of the heating rate in dynamic measurements (5–30°C/min) on kinetic parameters such as apparent activation energy (Ea) in TGA both in nitrogen and air were investigated. The Kissinger method was used to determine Ea for the degradation of pure PMMA and the PMMA/nano‐ZrO2 nanocomposites. The kinetic results show that the values of Ea for the degradation of the nanocomposites were higher than that of pure PMMA in air. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and application of a new vinyl copolymer superplasticizer
Authors: Lu Sheng‐Hua , Liu Gang , Ma Yan‐Fen , Li Fang 
Published: March 2010

AbstractA new vinyl graft copolymer superplasticizer was synthesized by copolymerization of polyethylene glycol acrylate (PEGAA), polyethylene glycol biester of maleic acid and citric acid (PEGMC), acrylic acid (AA), sodium allylsulphonate (SAS), and methyl acrylate (MA). The effects of the vinyl monomers' molar ratio, initiator, reaction temperature, and reaction time on its application properties were investigated. The results show that the new vinyl graft copolymer superplasticizer has excellent application properties when the molar ratio of PEGAA, PEGMC, AA, SAS, and MA is 0.5 : 0.10 : 0.20 : 0.05 : 0.03 and the initiator ammonium persulfate [(NH4)2S2O8, APS] is 0.8 wt % at 80°C for 3 h. The vinyl monomers' conversion is 98.7%. The applied results show that the water‐reducing ratio and retardation solidification time of the superplasticizer reach 33.5% and 4 h, respectively. The applied concrete has excellent mechanical properties. Its molecular structure was characterized by nuclear magnetic resonance, Fourier transform infrared spectra, and gel permeation chromatography. It is characteristic of the new vinyl graft copolymer superplasticizer that citric acid (CA) and MA are introduced into the copolymer molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Atmospheric pressure plasma enhanced synthesis of flame retardant cellulosic materials
Authors: Totolin Vladimir , Sarmadi Majid , Manolache Sorin O. , Denes Ferencz S. 
Published: March 2010

AbstractFlame retardant cellulosic materials have been produced using a silicon dioxide (SiO2) network coating. SiO2 network armor was prepared through hydrolysis and condensation of the precursor tetraethyl orthosilicate (TEOS), prior coating the substrates, and was cross linked on the surface of the substrates using atmospheric pressure plasma (APP) technique. Because of protection effects of the SiO2 network armor, the cellulosic based fibers exhibit enhanced thermal properties (characterized by TGA and DSC) and improved flame retardant (proven by ASTM D1230‐99). Furthermore, the surface analysis (XPS and SEM) confirmed the presence of the SiO2 network attached to the substrates even after intense ultrasound washes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A review of factors influencing user satisfaction in information retrieval
Authors: Al‐Maskari Azzah , Sanderson Mark 
Published: March 2010

AbstractThe authors investigate factors influencing user satisfaction in information retrieval. It is evident from this study that user satisfaction is a subjective variable, which can be influenced by several factors such as system effectiveness, user effectiveness, user effort, and user characteristics and expectations. Therefore, information retrieval evaluators should consider all these factors in obtaining user satisfaction and in using it as a criterion of system effectiveness. Previous studies have conflicting conclusions on the relationship between user satisfaction and system effectiveness; this study has substantiated these findings and supports using user satisfaction as a criterion of system effectiveness.
X‐ and H‐Shape Two Dimensional Conjugated Oligomers with Anthracene as the Node
Authors: Cui Weibin , Fu Yingying , Qu Yao , Tian Hongkun , Zhang Jingping , Xie Zhiyuan , Geng Yanhou , Wang Fosong 
Published: March 2010

AbstractX‐ and H‐shape two‐dimensional (2D) conjugated oligomers (X‐ and H‐mers) and relevant model compounds have been synthesized through the introduction of different conjugated segments at the 9,10 and 2,6‐positions of anthracene, and their properties were studied in detail. Comparing with the model compounds, the X‐ and H‐mers are featured with broader absorption spectra and narrower energy bandgaps. Computational studies on the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) also indicate that these X‐ and H‐mers are 2D conjugated. Solution processed bulk heterojunction (BHJ) solar cells with [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) as the acceptor material exhibited the power conversion efficiency (PCE) up to 0.53 %.
Exact controllability of wave equations with variable coefficients coupled in parallel
Authors: Wu Jieqiong , Li Shengjia , Chai Shugen 
Published: March 2010

AbstractIn this paper, we investigate exact controllability for coupled wave equations which have variable coefficients principal part. Observability inequality is obtained by using Riemannian geometry method and Carleman estimates. Furthermore, the exact controllability result is established with Dirichlet boundary controls when T>T0, where the lower bound T0 for the control time T is different from that obtained in the constant coefficient principal part case.Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Rapid construction and characterization of synthetic antibody libraries without DNA amplification
Authors: Ge Xin , Mazor Yariv , Hunicke‐Smith Scott P. , Ellington Andrew D. , Georgiou George 
Published: March 2010

AbstractWe report on a simple method to rapidly generate very large libraries of genes encoding mutant proteins without the use of DNA amplification, and the application of this methodology in the construction of synthetic immunoglobulin variable heavy (VH) and light (Vκ) libraries. Four high quality, chemically synthesized polynucleotides (90–140 bases) were annealed and extended using T4 DNA polymerase. Following electroporation, >109 transformants could be synthesized within 1 day. Fusion to β‐lactamase and selection on ampicillin resulted in 3.7 × 108 VH and 6.9 × 108 Vκ clones highly enriched for full‐length, in‐frame genes. High‐throughput 454 DNA sequencing of >250,000 VH and Vκ genes from the pre‐ and post‐selection libraries revealed that, in addition to the expected reduction in reading‐frame shifts and stop codons, selection for functional expression also resulted in a statistical decrease in the cysteine content. Apart from these differences, there was a good agreement between the expected and actual diversity, indicating that neither oligonucleotide synthesis nor biological constrains due to protein synthesis of VH/Vκ‐β‐lactamase fusions introduce biases in the amino acid composition of the randomized regions. This methodology can be employed for the rapid construction of highly diverse libraries with the near elimination of PCR errors in invariant regions. Biotechnol. Bioeng. 2010; 106: 347–357. © 2010 Wiley Periodicals, Inc.