bluuebunny/crossref_metadata_2025 huggingface dataset:
Immobilization of borate waste simulate in cement–water extended polyester composite based on poly(ethylene terephthalate) waste, part 3: Behavior of solid waste form during a scenario of flooding accident in the disposal site
Authors: Tawfik M. E. , Eskander S. B.
Published: March 2007

Laboratory scale testing program was conducted to investigate the feasibility of using water extended polyester cement composite (PCC) based on poly‐ (ethylene terephthalate) waste (PET) as immobilization matrix for borate waste, originated from pressurized water reactors (PWRs), during prolonged term of disposal process and in scenario of flooding accident. Twenty‐eight days cured solid blocks prepared as a premix of 3% by weight of the water extended polyester (WEP) and ordinary Portland cement (OPC) past having 40% by weight water were subjected to static immersion in three type of leachants, namely tap, sea, ground water. Weight changes, compressive strength variations, porosity, water absorption, and some other physical properties of the solid PCC waste forms were evaluated during 260 days of the static immersion. X‐ray diffraction (XRD), infrared analysis (IR), and electron scanning microscope were performed for the waste forms at the end of immersion prolonged period to follow the internal changes in the solid waste forms that may occur due to the corrosion action of the different leachants. The results obtained from the different measurements confirm the performance of the PCC solidified waste form, based on the mentioned formulation, as an acceptable matrix in the various disposal sites and for extended disposal time even at the worst flooding environment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4113–4120, 2007
Evaluation of new conducting polymeric membrane based on sulfonation of compatibilized NR/EPDM blend
Authors: El Sayed A. Mounir
Published: March 2007

In this study, research was undertaken to obtain new conducting polymer blend membrane based on compatibilized natural rubber/ethylene–propylene–diene monomer (NR/EPDM) by using different compatibilizers. To utilize them as membranes in polymer electrolyte membrane fuel cells, the blend membranes become conducting by sulfonation reaction, which inserts SO3H groups into the macromolecular chain. The polymer blend membrane ratio (50/50), which was compatibilized by polyacrylonitrile compound was selected among the entire blend studied (A6), with the aim of determining its conductivity and water and methanol permeabilities. The degree of compatibility of NR/EPDM blend was improved by the use of polyacrylonitrile compounds as compatibilizers. The effect of these compounds on the compatibility of blend was evaluated by ultrasonic spectroscopy and differential scanning calorimetry, DSC. It was found that a good compatibility has been achieved by using polyacrylonitrile because of the nitrile groups. When the polymer blend membrane (A6) was sulfonated with SO3H groups good perspectives were shown regarding the methanol and water permeabilities and physical properties comparing to the commercial Nafion one. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3804–3812, 2007
Thermal and crystallization behaviors of polyethylene blends synthesized by binary late transition metal catalysts combinations
Authors: Pan L. , Zhang Kun Y. , Li Yan G. , Bo Shu Q. , Li Yue S.
Published: March 2007

A series of reactor blends of linear and branched polyethylenes have been prepared, in the presence of modified methylaluminoxane, using a combination of 2,6‐bis[1‐(2,6‐dimethyphenylimino) pyridyl]‐cobalt(II) dichloride (1), known as an active catalyst for producing linear polyethylene, and [1,4‐bis(2,6‐diidopropylphenyl)] acenaphthene diimine nickel(II) dibromide (2), which is active for the production of branched polyethylene. The polymerizations were performed at various levels of catalyst feed ratio at 10 bar. The linear correlation between catalyst activity and concentration of catalyst 2 suggested that the catalysts performed independently from each other. The weight‐average molecular weights
$ {({\overline{M}}_{w})} $, crystalline structures, and phase structures of the blends were investigated, using a combination of gel permeation chromatography, differential scanning calorimetry, wide‐angle X‐ray diffraction, and small angle X‐ray scattering techniques. It was found that the polymerization activities and MWs and crystallization rate of the polymers took decreasing tendency with the increase of the catalyst 2 ratios, while melting temperatures (Tm), crystalline temperatures (Tc), and crystalline degrees took decreasing tendency. Long period was distinctly influenced by the amorphous component concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4188–4198, 2007
Uptake of aromatic solvents by polyethylene films
Authors: Igwe Isaac O.
Published: March 2007

The sorption properties of the solvents benzene, toluene, and xylene in polyethylene films at 40, 60, and 80°C were investigated. The diffusion coefficient increased with an increase in the sorption temperature for the solvents and was highest for xylene and least for benzene. The inability of xylene to show a definite order of the diffusion coefficients at the investigated temperatures was attributed to the presence of two methyl side groups in the molecule. The solubilities of the solvents in polyethylene increased with an increase in the sorption temperature, and the following order of the solubilities could be observed: xylene > toluene > benzene. The permeabilities of the solvents in polyethylene depended on the sorption temperature, and the following order of the permeabilities was observed: xylene > toluene > benzene. The calculated activation energies of sorption in polyethylene films were all positive; benzene had the highest energy of sorption, and xylene had the lowest. The calculated enthalpies of sorption (ΔHS) were also positive for the three solvents and were in the following order: xylene > toluene > benzene. The calculated entropies of sorption (ΔS) were negative for the solvents and showed trends similar to the variation of ΔHS among the solvents. The change in the Gibbs free energies of sorption (ΔGS), evaluated with the expression ΔGS = ΔHS − TΔS (where T is the Kelvin temperature), were all positive, and this was an indication of the nonspontaneity of the solubility of polyethylene in the aromatic solvents at 313 K. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3849–3854, 2007
Synthesis of formaldehyde polymers from benzene‐1,2‐diol, phenolic alkane‐1,2‐diol, and phenolic alkane‐1,3‐diol as immobilized chelatants for borate anion
Authors: Tyman John H. P. , Payne Peter B.
Published: March 2007

A variety of phenolic aryl‐1,2‐ and 1,3‐diols have been condensed with formaldehyde to form polymers serving as immobilized chelatants for borate anions. In this way, polymers from 1,2‐dihydroxybenzene, 2‐hydroxymethylphenol, and a 3‐methyl derivative (saligenins) and 2‐(4‐hydroxyphenyl)‐propane‐1,3‐diol have been converted into formaldehyde polymers with an increasing level of conformational mobility in the diol moiety of the polymer. The extraction of borate from alkaline solutions with three types of polymers has been examined, and the polymer containing planar 1,2‐dihydroxybenzene has been found to be superior to a saligenin‐ and 2‐(4‐hydroxyphenyl)‐ propane‐1,3‐diol‐derived polymer. This suggests that conformational mobility is not an important structural feature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Crystallization behaviors of linear and long chain branched polypropylene
Authors: Tian Jinghua , Yu Wei , Zhou Chixing
Published: March 2007

The nonisothermal crystallization kinetics of linear and long chain branched polypropylene (LCB PP) were investigated by differential scanning calorimetry (DSC) at various cooling rates. Several methods such as Avrami, Ozawa, and Jeziorny were applied to describe the crystallization process of linear PP and LCB PPs with different LCB level under nonisothermal conditions. The values of t1/2, Zc, and F(T) show that LCB has the role of heterogeneous nucleating agent and accelerates the crystallization process of PP. Moreover, the Kissinger method was used to evaluate the activation energy of linear PP and LCB PPs. The result shows that the activation energy of LCB PPs are higher than that of linear PP, indicating that the presence of LCB baffles the transfer of macromolecular segments from PP melt to the crystal growth surface. Furthermore, the crystal morphology of linear PP and LCB PPs was observed through polarized optical microscopy (POM), and fine spherulites were observed for LCB PPs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3592–3600, 2007
Effects of polymethylvinylsilicone oil with side tetraphenylphenyl groups on the radiation resistance of addition‐type silicone rubber
Authors: Jiang Zhigang , Zhang Jie , Feng Shengyu
Published: March 2007

Polymethylvinylsilicone oil with side tetraphenylphenyl groups (called C2 gum for short) as a low molecular additive was used in two kinds of addition‐type silicone rubber, polymethylvinyl silicone rubber and poly (dimethyl‐diphenyl) silicone rubber, and the radiation resistance of silicone rubbers obtained was investigated by γ‐rays radiation with the dose rate of 117 Gy/min at doses up to 350, 500, and 850 kGy, respectively. Moreover, the average molecular weight between crosslinks and mechanical properties of silicone rubbers after irradiated in air and N2 were determined by toluene‐swelling method and on a XLS‐A rubber test instrument, respectively. The results show that C2 gum can effectively improve the radiation resistance of silicone rubber. When C2 gum is used in poly(dimethyl‐diphenyl) silicone rubber, phenyl groups and tetraphenylphenyl groups may have synergistic effect, and the radiation resistance is improved greatly. The suitable amount of C2 gum used in silicone rubber is 10– 14 phr. The crosslinking density of vulcanizates irradiated in N2 is higher than that of vulcanizates irradiated in air because of the oxidative degradation. The radiation protection mechanism of C2 gum was also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4144–4148, 2007
Synthesis of functionalized double‐cylinder‐type copolymer brushes and crosslinking of internal cylindrical domains
Authors: Ishizu Koji , Takano Satoshi , Ochi Koichiro
Published: March 2007

Photoinduced atom transfer radical polymerization (ATRP) was applied to the synthesis of double‐cylinder‐type copolymer brushes. The procedure included the following steps: (1) photoinduced ATRP of multifunctional polystyrene (PSDC) having N,N‐diethyldithiocarbamate (DC) pendant groups with t‐butyl acrylate (BA) and (2) subsequent photoinduced ATRP of methyl methacrylate (MMA) with this PBA brush polyinitiator provided double‐cylinder‐type brushes [PSDC‐graft‐(PBA‐block‐PMMA)]. Solution properties of such double‐cylinder‐type brushes were investigated by dynamic light scattering. As a result, these copolymer brushes exhibited an isotropic conformation in solution. After hydrolysis of PBA blocks, we obtained amphiphilic copolymer brushes: PSDC‐graft‐[poly(acrylic acid) (PAA)‐block‐PMMA]. Crosslinking of PAA internal cylindrical domains was performed by the reaction of PAA blocks with ethylenediamine. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3994–4000, 2007
Investigation of styrene/1‐hexene copolymerization by homogeneous and heterogeneous bisindenyl ethane zirconium dichloride catalyst system
Authors: Rahmani Sohrab , Abbasian Mojtaba , N. Moghadam Peyman , A. Entezami Ali
Published: March 2007

Homogeneous copolymerization of styrene and 1‐hexene was carried out in toluene at room temperature using bisindenyl ethane zirconium dichloride/methylaluminoxane (MAO). The supported catalyst was prepared with immobilization of Et(Ind)2ZrCl2/MAO on silica (calcinated at 500°C) with premixed method. Heterogeneous copolymerization of styrene/1‐hexene with different mole ratios was carried out in the presence of supported catalyst system. The copolymers obtained from homogeneous and heterogeneous catalyst system were characterized by 1H NMR and 13C NMR. Composition of the resulting copolymers was determined by 1H NMR data. Analysis of 13C NMR spectra of obtained copolymers by homogeneous and heterogeneous catalyst systems present isotactic olefin‐enriched copolymers. Molecular weight and thermal behavior of resulting copolymers was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4008–4014, 2007
Platinum and palladium ions adsorption at the trace amounts by radiation crosslinked carboxymethylchitin and carboxymethylchitosan hydrogels
Authors: Wasikiewicz Jaroslaw M. , Mitomo Hiroshi , Seko Noriaki , Tamada Masao , Yoshii Fumio
Published: March 2007

Adsorption of palladium and platinum ions at the trace amounts onto radiation crosslinked carboxymethylchitin (CMCht) and carboxymethylchitosan (CMChts) has been investigated. Maximum adsorption capacities for palladium were 2.679 and 1.053 mg/g dry gel, whereas for platinum they were 2.513 and 1.155 mg/dry gel for CMCht and CMChts, respectively. Retention capacity values for palladium were 0.45 and 0.06; for platinum 0.25 and 0.11 mEquiv./g for CMCht and CMChts, correspondingly. It has been shown that adsorption of Pd and Pt ions onto both hydrogels were dependent on the chloric and nitric ions concentration. Desorption experiments in HCl and HNO3 solutions proved that adsorption is governed by chelating mechanism rather than ion‐exchange one. SEM‐EDX spectroscopy showed that palladium and platinum ions were homogeneously distributed in all sections of hydrogel matrix. DSC experiments demonstrated decreasing in the decomposition temperature of polymers after inclusion of palladium and platinum ions, suggesting that metals are causing lowering of stability in polymer structural integrity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4015–4023, 2007
Properties of pH‐dependent tertiary amine‐based gels as potential drug delivery matrices
Authors: Pardini O. R. , Amalvy J. I. , François N. , Daraio M. E.
Published: March 2007

The rheological and morphological properties and in vitro theophylline release of tertiary amine‐based microgels were evaluated. The testing of such a formulation through in vitro diffusion experiments revealed that the release of theophylline from the microgels was pH‐dependent and differs significantly with respect to a nonresponsive gel like scleroglucan (Scl). The microgels were obtained from 2‐(diethyl amino) ethylmethacrylate (DEA) in the presence of a bifunctional crosslinker at pH 8–9. As the resulting microgels are pH‐responsive and an increase in viscosity from high to low pH range is exhibited, the in vitro release of theophylline as model drug was studied at different pHs of both the matrix and the receptor medium. The release behaviors of PDEA‐based microgels were compared to nonresponsive natural gel Scl, studied previously. For microgels, diverse release patterns were found at different acidity conditions. This observation seems to be related to complex diffusion phenomena and the different gel structure obtained for samples prepared at dissimilar pH. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4035–4040, 2007
Polyimide‐silica nanocomposites exhibiting low thermal expansion coefficient and water absorption from surface‐modified silica
Authors: Tang J. C. , Lin G. L. , Yang H. C. , Jiang G. J. , Chen‐Yang Y. W.
Published: March 2007

In this study, a commercially available nano‐sized silica (SiO2) was surface‐modified via esterification with oleic acid (OA), a relatively inexpensive and hydrophobic modifier, and characterized by FTIR, NMR, SEM, EDS, and TGA measurements. Various amounts of the surface‐modified silica nanoparticles (SiO2‐OA) were dispersed in a poly(amic acid), which were then cyclized at high temperatures to form a series of PI/SiO2‐OA nanocomposite films (PISA). The effect of the addition of the SiO2‐OA nanoparticles on the properties of the as‐prepared polyimide nanocomposite was studied. The results indicated that, comparing with pure PI and PI/pristine‐SiO2 composite film (PISI), the as‐prepared PISA films had enhanced dynamic mechanical properties and thermal stability, as well as reduced water absorption and thermal expansion. The as‐prepared PI/SiO2‐OA nanocomposites have potential for applications in high performance microelectronic devices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104, 4096–4105, 2007
Carbon nanofibre‐reinforced ultrahigh molecular weight polyethylene for tribological applications
Authors: Galetz M. C. , Blaβ T. , Ruckdäschel H. , Sandler J. K. W. , Altstädt V. , Glatzel U.
Published: March 2007

Carbon nanofibre (CNF)‐reinforced ultrahigh molecular weight polyethylene (UHMWPE) nanocomposites containing up to 10 wt % of nanofibres were prepared by a novel solvent‐assisted extrusion process using short chain oligomers to tailor the melt viscosity of the UHMWPE matrix. A detailed investigation of the resulting nanocomposite microstructure and of the static mechanical properties revealed that the carbon nanofibres lead to improved mechanical properties of the UHMWPE related to the wear performance of such systems. Unidirectional sliding tests against a 100Cr6 steel under dry conditions verified the significant potential of dispersed carbon nanofibres to reduce the wear rate of this polymer. In light of the promising results, a further optimization of the processing conditions of such UHMWPE nanocomposites is expected to yield interesting future nanocomposite materials even for demanding applications such as artificial knee implants. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4173–4181, 2007
Synthesis and properties of poly(aryl ether ketone ketone)/poly(aryl ether ether ketone ketone) copolymers with pendant cyano groups
Authors: Yu Yikai , Xiao Fen , Cai Mingzhong
Published: March 2007

2,6‐Diphenoxybenzonitrile (DPOBN) was synthesized by reaction of phenol with 2,6‐difluorobenzonitrile in N‐methyl‐2‐pyrrolidone in the presence of KOH and K2CO3. Poly(aryl ether ketone ketone)/poly(aryl ether ether ketone ketone) copolymers with pendant cyano groups were prepared by the Friedel–Crafts electrophilic substitution reaction of terephthaloyl chloride with varying mole proportions of diphenyl ether and DPOBN using 1,2‐dichloroethane as solvent and N‐methyl‐2‐pyrrolidone as Lewis base in the presence of anhydrous AlCl3. The resulting polymers were characterized by various analytical techniques, such as FT‐IR, differential scanning calorimeter, thermal gravimetric analysis, and wide‐angle X‐ray diffraction. The crystallinity and melting temperature of the polymers were found to decrease with increase in concentration of the DPOBN units in the polymer. Thermogravimetric studies showed that all the polymers were stable up to 514°C in N2 atmosphere. The glass transition temperature was found to increase with increase in concentration of the DPOBN units in the polymer when the molar ratios of DPOBN to DPE ranged from 10/90 to 30/70. The copolymers containing 30–40 mol % of the DPOBN units exhibit excellent thermostability at (350 ± 10)°C and have good resistance to acidity, alkali, and organic solvents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3601–3606, 2007
Synthesis of high molecular weight polyoxyethylene with a quaternary catalyst and study of its conductive blends with poly(2‐vinyl pyridine)
Authors: Xie Hong‐Quan , Zhang Ji‐Hong , Cui Min‐Hui , Xie Dong
Published: March 2007

High molecular weight polyoxyethylene (PEO) was synthesized by using a quaternary catalyst composed of triisobutyl aluminum, phosphoric acid, water, and N,N‐dimethylaniline (DMA). Optimum synthesis conditions and some properties of the product were studied. This catalyst showed high activity and the molecular weight of the polyoxyethylene obtained can approach one million. The activity of polymerization mainly depends upon the composition of catalyst. The optimum composition is as follows: i‐Bu3Al:H3PO4:H2O:DMA = 1 : 0.17 : 0.17 : 0.10–0.15 (molar ratio).The active centers of the catalyst was thus proposed. The high molecular weight PEO synthesized by this catalyst was blended with poly(2‐vinyl pyridine) (PVP) and then doped with LiClO4 and TCNQ to obtain a conductive elastomeric material. Ionic, electronic, and mixed (ionic–electronic) conductivities of blends were investigated. At a Li/EO molar ratio of 0.1 and a TCNQ/VP molar ratio of 0.5, the mixed conductivity of the blend of PEO/PVP/LiCIO4/TCNQ is higher than the sum of ionic conductivity of PEO/PVP/LiCIO4 and electronic conductivity of PEO/PVP/TCNQ, when the weight ratio of PEO to PVP is 6/4 or 5/5. It can reach 4 × 10−6 S/cm at room temperature. Differential scanning calorimetry, thermal gravimetric analysis, and the appearance of the blend showed that both TCNQ and LiClO4 can complex with PEO and PVP, thus enhancing the compatibility between PEO and PVP. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation and characterization of aqueous polyurethane dispersions containing ionic centers
Authors: Barikani M. , Valipour Ebrahimi M. , Seyed Mohaghegh S. M.
Published: March 2007

Aqueous polyurethane dispersions were prepared from toluene di‐isocyanate, polytetramethylene glycol, and 1,4‐butanediol, with different weight percent of dimethylol propionic acid (DMPA) as anionic center. IR Spectroscopy was used to follow the polymerization reaction as well as the polymer characterization. The effect of DMPA content on the state of dispersion, particle size distribution, mechanical, and thermal properties of the emulsion‐cast films were studied. Average particle size of the prepared emulsion polyurethanes decreased with increasing DMPA content. Tensile strength and hardness increase and elongation at break and contact angle decrease by increasing the ionic content. Glass transition temperature (Tg) shifted toward higher temperature and thermal stability decreased by increasing the DMPA content. The increased Tg and tensile properties are interpreted in terms of the increased hard segments and coulombic forces between ionic centers. The decreased contact angle is ascribed to the increase in the hydrophilicity of the polyurethanes because of the incorporation of more hydrophilic moiety in polymer backbone. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3931–3937, 2007
Effect of cellulase pretreatment of raw and bleached cotton fibers on properties of hydroentangled nonwoven fabrics
Authors: Verenich S. , Arumugam K. , Shim E. , Pourdeyhimi B.
Published: March 2007

This study was undertaken to investigate the effect of enzymatic pretreatment of cotton (polysaccharides) fibers on the properties of resulting nonwoven fabric. Enzymatic treatment is known to improve the esthetical properties of fabrics but will likely lead to a reduction in strength. In the case of nonwovens the strength loss can be even more drastic as cellulase may attack bonded areas of the fabric. In this work, raw and bleached cotton fibers were treated with enzyme solutions prior to fabric formation to avoid possible damage to the bonded areas and improve strength retention. These fibers were first modified with commercially available whole cellulases and monocomponent endoglucanase enzyme solutions. Then they were formed into a fabric and bonded via hydroentangling. Parameters such as bending modulus, fabric tenacity, fiber strength, length and reducing power were measured for each sample. The pretreatment of cotton fibers prior to fabric formation showed that the resulting nonwovens could be stronger and more drapeable than the same fabric composed of untreated fibers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Application of polypyrrole to flexible substrates
Authors: Winther‐Jensen Bjørn , Clark Noel , Subramanian Priya , Helmer Richard , Ashraf Syed , Wallace Gordon , Spiccia Leone , MacFarlane Douglas
Published: March 2007

Conducting polymers such as polypyrrole may be useful in smart packaging products, provided application methods can be developed that circumvent the insolubility and infusibility of these materials. Experiments were conducted in five research areas relevant to the application of polypyrrole to nonrigid substrates. The studies reveal that application of polypyrrole from the liquid phase, either by deposition from depleted bulk solution or inkjet printing dispersions, is unlikely to give films as regular as those produced by vapor phase polymerization. Using the latter approach, two potential methods of applying patterned polypyrrole films to nonrigid substrates were developed. The first used hypochlorite to pattern a continuous film of polypyrrole, previously applied by vapor phase polymerization. The second used inkjet printing to apply an oxidant solution, whose pH had been raised with a volatile base, to nonrigid substrates. The higher pH reduced corrosion of the print head, increasing the lifetime of printers exposed to oxidative compounds. The base was subsequently evaporated by heating, and the dried oxidant used as a template for vapor phase polymerization of polypyrrole. This method gave smooth, shiny and adherent polypyrrole films on papers and polyester transparency, with high resolution. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3938–3947, 2007
Synthesis of macroporous poly(N‐isopropylacrylamide) hydrogel with ultrarapid swelling–deswelling properties
Authors: Zhao Qian , Sun Jianzhong , Zhou Qiyun
Published: March 2007

A novel technique to synthesize a macroporous poly(N‐isopropylacrylamide) hydrogel with ultrarapid swelling–deswelling properties by using dodecyl dimethyl benzyl ammonium bromide (DDBAB) during the polymerization/crosslinking reaction at −8°C was proposed. A hydrophobic initiator dodecyl dimethyl benzyl ammonium persulfate (APS) was proved to be produced in situ by the reaction of DDBAB and the water‐soluble initiator APS and a heterogeneous initiation mechanism was proposed. The scanning electron microscope and environmental scanning electron microscope images showed that the pore size of the hydrogel increased with increase of the amount of DDBAB. The macroporous structure of hydrogel induced a large swelling ratio and rapid swelling–deswelling rate, since the free water could diffuse very quickly through the macroporous network. The time required from equilibrium swollen state to equilibrium shrunken state was only about 1 min and vice versa. The oscillating swelling–deswelling measurements showed that this macroporous hydrogel could be used repeatedly. These properties of ultrarapid response and reversibility are advantageous for several technical applications, as a kind of biomaterials, both in medicine and in biotechnology. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4080–4087, 2007
Preparation and photophysical behaviors of fluorescent chitosan bearing fluorescein: Potential biomaterial as temperature/pH probes
Authors: Guan Xiaolin , Liu Xinyu , Su Zhixing
Published: March 2007

A novel method for attaching fluorescein (via its epoxy derivative) to water‐soluble chitosan, and the temperature/pH‐sensitive qualities of fluorescence were investigated. 3‐Epoxypropoxy fluorescein (EPF) was firstly synthesized by the reaction between fluorescein and epichlorohydrin, and then water‐soluble chitosan bearing fluorescein (CS‐EPF) was prepared via ring‐opening reaction with EPF. They were characterized by the methods of 1H NMR, MS, IR, UV–Vis, and luminescence spectra, respectively. The chemiluminescent and photophysical behaviors of EPF and CS‐EPF were studied in detail. The results showed that the fluorescent chitosan could still provide temperature and pH sensitivities similar to that of fluo‐ rescein, achieving better long‐term stability and fast equilibrium response. CS‐EPF had an excellent linear response between relative fluorescence intensity and temperature in the range of 0–60°C and two linear relationships between relative fluorescence intensity and pH in 0.0–4.14 and 8.15–13.20, respectively. This investigation may provide a convenient way to prepare low‐cost and multifunctional macromolecule biomaterial to probe pH and temperature in biological systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3960–3966, 2007
Synthesis and characterization of a poly(ethylene glycol) prepolymer to be applied as a bioadhesive
Authors: Ferreira P. , Coelho J. F. J. , Pereira R. , Silva António F. M. , Gil M. H.
Published: March 2007

Surgical adhesives can be applied to wound closure and to covering and protecting surface wounds. Depending on their degradability, they can then slough off or can be reabsorbed by the organism when the wound initiates the healing process. In this work, we intended to develop a new urethane‐based bioadhesive that could accomplish these purposes. Urethanes are considered to be promising candidates as adhesives because of the possibility of their synthesis as prepolymers and therefore their reaction with amino groups present in the biological molecules. Some urethanes were obtained by the reaction of poly(ethylene glycol) with isophorone diisocyanate. The characterization of the various materials was accomplished with different techniques: attenuated total reflection/Fourier transform infrared, swelling‐capacity determination, the evaluation of the moisture‐curing kinetics, a reaction with aminated substrates (as a simulation of the living tissues), and the determination of the surface energy by contact‐angle measurements. The study of the thermal properties of the urethanes was performed by dynamical mechanical thermal analysis, differential scanning calorimetry, and thermogravimetric analysis. The hemocompatibility of the urethane was also evaluated by thrombosis and hemolysis tests. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Biodegradable poly(vinyl alcohol)‐graft‐ poly(ε‐caprolactone) comb‐like polyester: Microwave synthesis and its characterization
Authors: Yu Zhaoju , Liu Lijian
Published: March 2007

Poly(vinyl alcohol)‐initiated microwave‐assisted ring opening polymerization of ε‐caprolactone in bulk was investigated, and a series of poly(vinyl alcohol)‐graft‐poly(ε‐caprolactone) (PVA‐g‐PCL) copolymers were prepared, with the degree of polymerization (DP) of PCL side chains and the degree of substitution (DS) of PVA by PCL being in the range of 3–24 and 0.35–0.89, respectively. The resultant comb‐like PVA‐g‐PCL copolymers were confirmed by means of FTIR, 1H NMR, and viscometry measurement. The introduction of hydrophilic backbone resulted in the decrease in both melting point and crystallization property of the PVA‐g‐PCL copolymers comparing with linear PCL. With higher microwave power, the DP of PCL side chains and DS of PVA backbone were higher, and the polymerization reaction proceeded more rapidly. Both the DP and monomer conversion increased with irradiation time, while the DS increased first and then remained constant. With initiator in low concentration, the DP and DS were higher, while the monomer was converted more slowly. Microwaves dramatically improved the polymerization reaction in comparison of conventional heating method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104, 3973–3979, 2007
An investigation on the reinforcing potential of red earth as filler for natural rubber compounds
Authors: Osabohien E. , Egboh S. H. O.
Published: March 2007

Locally sourced red earth (RE) was air‐dried, pulverized, and screened with a sieve of mesh size 75 nm. It was characterized in terms of its moisture content, loss on ignition, silica content, iodine adsorption number, oil absorption, pH, and metal oxide compositions. Natural rubber, standard Nigerian rubber used for this work was first characterized in terms of its dirt, ash and nitrogen contents, volatile matter, plasticity retention index, and Mooney viscosity. The RE was applied as filler wholly and in blends with standard carbon black, CB (N330) filler in the natural rubber compounding using efficient vulcanization system. The cure and the physicomechanical properties of the compounds and vulcanizates were, respectively, measured as function of filler loading. The results were compared with those of the standard carbon black (N330)‐filled natural rubber. It was found, that the RE‐filled natural rubber showed substantial reinforcement of the rubber, though inferior to carbon black (N330) filled vulcanizates, the tensile strength of the carbon black‐filled vulcanizates is about one half times that of the RE‐filled vulcanizates. The tensile properties of the RE‐filled vulcanizates improved markedly by blending the RE‐filler with the carbon black (N330). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
HPLC determination of safflor yellow A and three active isoflavones from TCM Naodesheng in rat plasma and tissues and its application to pharmacokinetic studies
Authors: Yu Zhiguo , Gao Xiaoxia , Zhao Yunli , Bi Kaishun
Published: March 2007

A high‐performance liquid chromatographic method was developed for the simultaneous determination and pharmacokinetic studies of safflor yellow A, puerarin, 3′‐methoxyl‐puerarin, and puerarinapioside in the plasma and tissues of rats that had been administered with the traditional Chinese medicine (TCM) preparation Naodesheng via the caudal vein. Samples taken from rats were subjected to protein precipitation with acetone. Separation of these four compounds was accomplished on a Kromisil C18 stationary phase using a mobile phase of acetonitrile–0.1% phosphoric acid–tetrahydrofuran (8:92:2, v/v/v) at a flow‐rate of 1.0 mL/min. The detection wavelength was set at 250 nm. The calibration curves of the four components were linear in the given concentration ranges. The intra‐ and inter‐day precisions in plasma and tissues were less than 15% and the extraction recoveries were higher than 60%. The lower limits of quantitation of four components were low enough to determine the four components. These four components all exhibited kinetics that fitted a two‐compartment model in rats. The elimination half‐life was 1.19 h for safflor yellow A, 2.69 h for puerarin, 2.94 h for 3′‐methoxyl‐puerarin, and 0.87 h for puerarinapioside, respectively. Following administration of a single injection of Naodesheng, the concentration (C) of the four components in the tissues showed Ckidney > Clung, Cliver > Cspleen, Cstomach, Cheart, approximately. The method is a reliable tool for performing studies of safflor yellow A and three puerarin isoflavones in different biological material. Copyright © 2007 John Wiley & Sons, Ltd.
An improved high‐performance liquid chromatographic method with a solid‐phase extraction for the determination of piperacillin and tazobactam: application to pharmacokinetic study of different dosage in Chinese healthy volunteers
Authors: Xia Chun‐hua , Xiong Yu‐qing , Wang Guang‐ji
Published: March 2007

An improved HPLC method was developed for the determination of piperacillin and tazobactam in human plasma and pharmacokinetic study in Chinese healthy volunteers. Piperacillin and tazobactam in human plasma were extracted by solid‐phase extraction and separated on a C18 column and detected at 220 nm. The mobile phase for piepracillin consisted of 0.01 mol/L sodium dihydrogen phosphate (pH = 4.65) and acetonitrile (71:29, v/v), and that for tazobactam was 0.05 mol/L sodium dihydrogen phosphate (pH = 4.45) and methanol (90:10, v/v). The method was linear in the range 0.25–320.00 µg/mL for piperacillin (r2 = 0.995) and 0.25–64.00 µg/mL for tazobactam (r2 = 0.994). The lower limit of quantification of both compounds was 0.25 µg/mL. The intra‐ and inter‐day precisions of piperacillin and tazobactam at three concentrations were all less than 9.2% and accuracies were within the range 97.0–108.0%. The method was used to investigate the pharmacokinetics of piperacillin and tazobactam in 12 volunteers who were intravenously given a dosage of 1.25, 2.50 and 3.75 g in three periods. The results showed that piperacillin sodium–tazobactom sodium (4:1) for injection in Chinese people fits linear dynamics, and the administred dosage can be adjusted with therapeutic effect. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous determination of panax notoginsenoside R1, ginsenoside Rg1, Rd, Re and Rb1 in rat plasma by HPLC/ESI/MS: platform for the pharmacokinetic evaluation of total panax notoginsenoside, a typical kind of multiple constituent traditional Chinese medicine
Authors: Li Xiaoyu , Sun Jianguo , Wang Guangji , Hao Haiping , Liang Yan , Zheng Yuanting , Yan Bei , Sheng Longsheng
Published: March 2007

A platform for the pharmacokinetic study of multiple constituent traditional Chinese medicine was developed and validated. An HPLC/ESI/MS method was employed for the simultaneous determination of panax notoginsenoside R1, ginsenoside Rg1, Rd, Re and Rb1 in rat plasma. After the addition of digoxin as an internal standard (IS), rat plasmas were extracted with n‐butanol saturated with pure water and all analytes were separated on a reversed‐phased C18 column with a mobile phase of acetonitrile–water (0.5 mm ammonium chloride) and pumped at a flow rate of 0.2 mL/min. Analytes were determined in a single quadrupole mass spectrometer using an electrospray ionization source. HPLC/ESI/MS was performed in the selected‐ion monitoring mode with the chlorinated adducts of molecular ions [M + Cl] − at m/z 967.75, 835.80, 981.80, 981.80, 1143.65 and 815.40 for R1, Rg1, Rd, Re, Rb1 and digoxin, respectively. The method showed excellent linearity over the concentration range 3.03–775.00 ng/mL (r2 = 0.9994) for R1, 4.00–1025.00 ng/mL (r2 = 0.9991, 0.9988, 0.9991) for Rg1, Rd and Re, respectively, and 2.77–710.00 ng/mL for Rb1 (r2 = 0.9990). The low limit of quantification was 3.03, 4.00, 4.00, 4.00 and 2.77 ng/mL for R1, Rg1, Rd, Re and Rb1, respectively, with S/N > 10. The intra‐ and inter‐day precisions were below 12.00% and the accuracy was between −2.31 and +4.43% for all analytes. The extract recoveries of analytes were from 67.47 to 94.18%. All analytes were stable in rat plasma after storage for 12 h at ambient temperature, at 4°C for 12 h in the sample pool, at −20°C for 4 weeks and at −20°C for three thaw–freeze cycles. The HPLC/ESI/MS technique provided an excellent method for the simultaneous quantification of R1, Rg1, Rd, Re and Rb1 in rat plasma and was successfully applied to the pharmacokinetic study of a multiple‐constituent traditional Chinese medicine, total panax notoginsenoside (Xuesaitong injection). Copyright © 2007 John Wiley & Sons, Ltd.
Determination of imatinib mesylate and its main metabolite (CGP74588) in human plasma and murine specimens by ion‐pairing reversed‐phase high‐performance liquid chromatography
Authors: Oostendorp Roos L. , Beijnen Jos H. , Schellens Jan H. M. , Tellingen Olaf van
Published: March 2007

A sensitive reversed‐phase high‐performance liquid chromatographic (HPLC) method has been developed and validated for the determination of imatinib, a tyrosine kinase inhibitor, and its main metabolite N‐desmethyl‐imatinib (CGP74588) in human plasma and relevant murine biological matrices. A simple HPLC assay for the individual quantification of imatinib and CGP74588 in murine specimens has not been reported to date. Sample pre‐treatment involved liquid–liquid extraction with tert‐butyl‐methyl ether. Imatinib, CGP74588 (metabolite) and the internal standard 4‐hydroxybenzophenone were separated using a narrow bore (2.1 × 150 mm) stainless steel Symmetry C18 column and detected by UV at 265 nm. The mobile phase consisted of 28% (v/v) acetonitrile in 50 mm ammonium acetate buffer pH 6.8 containing 0.005 m 1‐octane sulfonic acid and was delivered at 0.2 mL/min. The calibration curve was prepared in blank human plasma and was linear over the dynamic range 10 ng/mL to 10 µg/mL). The accuracy was close to 100% and the within‐day and between‐day precisions were within the generally accepted 15% range. The validation results showed that the assay was selective and reproducible. This method was applied to study the pharmacokinetics of imatinib and its main metabolite in human and mice. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of calycosin‐7‐O‐β‐d‐glucopyranoside in rat plasma and urine by HPLC
Authors: Ye Guan , Ma Rong‐Rong , Li Zhi‐Xiong , Wang Hui , Zhu Hai‐Yan , Sun Zhao‐Lin , Huang Cheng‐Gang
Published: March 2007

A reversed‐phase high‐performance liquid chromatographic (HPLC) assay for calycosin‐7‐O‐β‐d‐glucopyranoside in rat plasma and urine with solid‐phase extraction (SPE) was developed. Rutin was employed as an internal standard. The mobile phase consisted of acetonitrile–water (16:84, v/v) at a flow rate of 1.0 mL/min. Detection was set at 280 nm. The limit of quantitation of calycosin‐7‐O‐β‐d‐glucopyranoside was 0.2 µg/mL in both plasma and urine. The standard curve was linear from 0.2 to 10.0 µg/mL in plasma, and 0.2 to 5.0 µg/mL in urine. Both intra‐ and inter‐day precision of the calycosin‐7‐O‐β‐d‐glucopyranoside were determined and their RSD did not exceed 10%. The method was successfully applied to the analysis of samples obtained from a basic pharmacokinetic study, in which calycosin‐7‐O‐β‐d‐glucopyranoside was administered orally to rats. Copyright © 2007 John Wiley & Sons, Ltd.
Separating Y‐predictive and Y‐orthogonal variation in multi‐block spectral data
Authors: Eriksson Lennart , Toft Marianne , Johansson Erik , Wold Svante , Trygg Johan
Published: March 2007

Spectral data (X) may contain (a) variation that is correlated to concentrations or properties (Y) of samples and (b) variation that is unrelated to the same Y. This paper outlines an approach by which both such sources of variation may be resolved. The approach is based on a combination of hierarchical modelling and orthogonal partial least squares (OPLS). OPLS is first used at the base hierarchical level. The output is a labelling of the resulting score vectors as representing Y‐predictive or Y‐orthogonal variation. OPLS is then also used at the top hierarchical level together with principal components analysis (PCA). With PCA the Y‐orthogonal X‐variation is analysed and interpreted. With OPLS the Y‐predictive X‐variation is examined. The applicability of the proposed strategy is illustrated using one multi‐block spectral data set. Copyright © 2007 John Wiley & Sons, Ltd.
Breaking Chemistry's Strongest Bond: Can Three‐Coordinate [M{N(R)Ar}3] Complexes Cleave Carbon Monoxide?
Authors: Christian Gemma , Stranger Robert , Petrie Simon , Yates Brian F. , Cummins Christopher C.
Published: March 2007

The reaction pathway for the interaction of CO with three‐coordinate TaIII, WIII and ReIII complexes (modelled on the experimental [M{N(tBu)Ar}3] system) has been explored by using density functional methods. Calculations show that CO binds without a barrier to [Re(NH2)3], forming the encounter complex [OCRe(NH2)3], which is stabilized by ≈280 kJ mol−1 relative to the reactants. The binding of [Ta(NH2)3] to the oxygen terminus of CO is inhibited by a barrier of only 20 kJ mol−1 and is followed by spontaneous cleavage of the CO bond to form the products [CRe(NH2)3] and [OTa(NH2)3]. The salient features of the potential energy surface are more favourable to CO cleavage than the analogous N2 cleavage by [Mo(NH2)3], which is less exothermic (335 vs. 467 kJ mol−1) and is impeded by a significant barrier (66 kJ mol−1). The ReIII/TaIII/CO system therefore appears to be an excellent candidate for cleaving the exceptionally strong CO bond under mild laboratory conditions. The related WIII/TaIII dimer, which significantly weakens but does not cleave the CO bond, may be a suitable alternative when the chemistry is to be performed on activated CO rather than on the strongly bound oxide and carbide cleavage products.
Industry–government interaction in the preparation of a new directive: Nokia, industry associations and EuP
Authors: Kautto Petrus
Published: March 2007

This article sheds light on the interaction between the European Commission and different stakeholders via an illustrative example, the preparation of a proposal for what is known as the EuP directive. The main aim is to inquire how a multinational Finnish corporation, Nokia, and related industry associations anticipated legislation under preparation and how they tried to influence the preparation process. Thus, it contributes to the discussion on the role of business in public policy. The paper is based on a combination of different data collection methods and it covers approximately the period from spring 2000 to July 2003. As a result, it highlights how industry associations, Nokia and some other major companies thoroughly reformulated the proposal using issue based strategies. Besides, it describes which venues Nokia selected for lobbying, and illustrates the dependency of the Commission on companies and interest groups as sources of information. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Two New Flavonoids from Bonannia graeca: a DFT‐NMR Combined Approach in Solving Structures
Authors: Rosselli Sergio , Bruno Maurizio , Maggio Antonella , Bellone Gabriella , Formisano Carmen , Mattia Carlo Andrea , Di Micco Simone , Bifulco Giuseppe
Published: March 2007

Two new cyclized C‐geranylated flavonoids, the dihydroflavonol bonanniol C (4a) and the flavanone bonannione B (6a), were isolated as minor compounds from the aerial parts of Bonannia graeca (Umbelliferae). Their structures were elucidated by a combined approach of extensive spectroscopic means and quantum mechanical methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthetic and Mechanistic Investigations on the Rearrangement of 2,3‐Unsaturated 1,4‐Bis(alkylidene)carbenes to Enediynes
Authors: Sahu Bichismita , Muruganantham Rajendran , Namboothiri Irishi N. N.
Published: March 2007

The synthesis of 3,4‐ene‐1,5‐diynes, the key structural moiety present in several naturally occurring antitumor antibiotics, from 1,2‐enedialdehydes under two different experimental conditions is reported. One method involves the dibromomethylenation of dialdehydes under Corey–Fuchs conditions (CBr4, Ph3P, and Zn) and treatment of the resulting tetrabromides with nBuLi or LDA to afford enediynes. The second method involves a base‐mediated reaction of enedialdehydes with diethyl (1‐diazo‐2‐oxopropyl)phosphonate (Bestmann–Ohira reagent) and subsequent transformation of the bis(diazo) compounds generated in situ to enediynes. While the transformation of bis(diazo) compounds to enediynes could take place exclusively through alkylidenecarbenes, generated in situ by geminal elimination of N2, an alternative pathway, involving the vicinal elimination of HBr to afford an intermediate bromoalkyne and its subsequent metal‐halogen exchange and protonation during workup, exists for the bis(dibromoalkylidenes). However, our deuterium‐labeling experiments with a model substrate, deuterated p‐methoxybenzylidene dibromide, established the predominance of the alkylidenecarbenes, generated in situ by metal‐halogen exchange and elimination, for this substrate and, by analogy, for the tetrabromides as well. The scope of this novel methodology was extended to the synthesis of various heteroatom‐based (S, Se, and P) enediynes by quenching the acetylides with suitable electrophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)