bluuebunny/crossref_metadata_2025_split huggingface dataset:
Working methods paper: Micro‐scale preparation and characterization of isotopically enriched monomethylmercury
Authors: Rodríguez Martín‐Doimeadios R. C. , Stoichev T. , Krupp E. , Amouroux D. , Holeman M. , Donard O. F. X. 
Published: August 2002

AbstractA synthesis method for the micro‐scale laboratory preparation of isotopically enriched monomethylmercury (MMHg) has been successfully established. This compound is an important standard for species‐specific isotope dilution analysis. The isotopically enriched MMHg has been synthesized from commercially available mercury oxide (201HgO) using methylcobalamin co‐enzyme as methylating agent. The time required is less than 2 h and the final yield is about 90%. The proposed method is faster than those previously reported in the literature. It allows work on a micro scale to control the use of expensive enriched isotope standard. It also allows control of unintentional formation of dimethylmercury. The enriched mercury‐containing reaction products were analyzed by capillary gas chromatography coupled to an inductively coupled plasma mass spectrometer after derivatization with sodium tetraethylborate. The isotopic composition, concentration, purity and stability of the synthesized, enriched MMHg have been investigated in order to establish standard protocols for MMHg isotope dilution analysis or isotope labeling incubation experiments. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and biological activity of novel N‐tert‐butyl‐N,N′‐substitutedbenzoylhydrazines containing 2‐methyl‐3‐(triphenylgermanyl)propoxycarbonyl
Authors: Wang Qing‐Min , Huang Run‐Qiu 
Published: August 2002

AbstractIn a search for new insect growth regulators with unusual biological properties and different activity spectrum, we thought that the preservation of the bioactive unit and the introduction of 2‐methyl‐3‐(triphenylgermanyl)propoxycarbonyl in N‐tert‐butyl‐N,N′‐dibenzoylhydrazine would enhance their larvicidal activities to a significant degree. Therefore, we designed and synthesized N′‐tert‐butyl‐N′‐[2‐methyl‐3‐(triphenylgermanyl)propoxycarbonyl]‐N‐benzoylhydrazine and analogs by two procedures. These novel compounds were characterized by elemental analyses, IR, and 1H NMR. At the same time, N‐tert‐butyl‐N‐substitutedbenzoylhydrazines were prepared by a new method, and some reactions involved were studied. The preliminary results indicate that some compounds have inhibitory effects against plant pathogenetic bacteria such as early blight of tomato. Copyright © 2002 John Wiley & Sons, Ltd.
Water–gas shift reaction catalyzed by mononuclear ruthenium complexes containing bipyridine and phenanthroline derivatives
Authors: Aguirre Pedro , Moya Sergio A. , Sariego Renato , Bozec Hubert Le , Pardey Alvaro J. 
Published: August 2002

AbstractRuthenium complexes of the type [RuL(CO)2Cl2], [RuL2Cl2], [RuL2(CO)(H2O)](PF6)2, [RuL2Cl]2(PF6)2, [RuL2(CO)Cl](PF6), and [RuL2(CO3)]·3H2O (where L is a bipyridine or phenanthroline derivative) dissolved in aqueous 2‐ethoxyethanol, and in a basic medium of KOH, triethylamine, or trimethylamine, catalyze the water‐gas shift reaction under mild conditions (PCO = 0.9 atm at 100 °C). Copyright © 2002 John Wiley & Sons, Ltd.
Comparison of relative viscosity measurement of polyvinylpyrrolidone in water by glass capillary viscometer and differential dual‐capillary viscometer
Authors: Wu Chi‐San , Senak Larry , Bonilla Jose , Cullen James 
Published: August 2002

AbstractThe relative viscosity (RV) of polyvinylpyrrolidone (PVP) with different molecular weights was measured with a glass capillary viscometer and with a differential dual‐capillary viscometer in water at different concentrations. For the differential dual‐capillary viscometer, RV increases with a decreasing flow rate, especially for high molecular weight PVP at a 1% concentration. A good agreement in the RV between the two methods can be obtained for PVP with different molecular weights and at various concentrations if an appropriate flow rate is selected for the differential dual‐capillary viscometer. Special precaution is needed when using the differential dual‐capillary viscometer to measure the viscosity of a pure solvent. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1312–1315, 2002
Production of hollow polymer particles by suspension polymerizations for ethylene glycol dimethacrylate/toluene droplets dissolving styrene–methyl methacrylate copolymers
Authors: Okubo M. , Konishi Y. , Inohara T. , Minami H. 
Published: August 2002

AbstractSuspension polymerizations for ethylene glycol dimethacrylate (EGDM)/toluene droplets dissolving styrene–methyl methacrylate copolymers with different compositions were carried out. Hollow particles were obtained independent of the copolymer composition. In suspension copolymerizations for EGDM/divinyl benzene/toluene droplets dissolving poly(methyl methacrylate), hollow particles were produced at high EGDM content, but not at low EGDM content. Preferential adsorption of the polymer formed by the suspension polymerizations at the interfaces of the droplets over the (co)polymers preliminarily dissolved therein was one of the key factors for the formation of the hollow structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1087–1091, 2002
Synthesis of terpolymers having a phospholipid polar group and poly(oxyethylene) in the side chain and their protein adsorption–resistance properties
Authors: Oishi Tsutomu , Tanaka Hiroaki , Yamasaki Hirohito , Onimura Kenjiro 
Published: August 2002

AbstractTerpolymers having phospholipid polar groups were synthesized from 2‐methacryloyloxyethyl phosphorylcholine (MPC), methacryloyl or acryloyl poly(oxyethylene) macromonomers (POEM) [(CH2CH2O)n (where n = 2–23); PEOM(2), PEOM(23), ME(9), Ph(6)], and n‐butyl methacrylate (BMA). The characteristics of these terpolymer membranes were investigated by water content (H) and X‐ray photoelectron spectroscopy. The content of water in the terpolymer increased with increasing content of MPC and length of oxyethylene units. The membranes of terpolymers were found to adsorb bovine serum albumin much less than those of poly(methyl methacrylate) and poly(BMA). Even though the contents of MPC in the terpolymer were 5 to 25 mol %, the terpolymer depressed BSA adsorption more than poly(MPC‐co‐BMA) consisting of 29 mol % of MPC. The use of terpolymer with POEM can decrease the amount of MPC in the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1092–1105, 2002
Electrorheological properties of poly(lithium‐2‐acrylamido‐2‐methyl propane sulfonic acid) suspensions
Authors: Ünal Halil Ibrahim , Yilmaz Haşim 
Published: August 2002

AbstractIn this study, poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) (PAMPS) was synthesized using potassium persulfate (K2S2O8) as initiator. PAMPS (Mn = 36,000 g/mol) was partially converted to a lithium salt (PAMPS–Li), and particle size was determined to be 40 μm. Suspensions of PAMPS–Li at various concentrations were prepared in silicone oil, mineral oil, dioctylphthalate (DOP), and trioctyltrimellitate (TOTM) insulating oils. Colloidal stabilities of these suspensions were determined at 20 and 80°C. The PAMPS–Li suspensions were observed to provide an electrorheological (ER) response upon the application of an external dc electric field. ER properties of these suspensions were investigated at various shear rates (γ˙) and electric field strengths (E). Further, effects of polar promoters and high temperature on ER activity were determined, and excess shear stresses (Δτ) were calculated. A shear‐thinning non‐Newtonian viscoelastic behavior was observed for the PAMPS–Li suspensions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1106–1112, 2002
Modeling of “living” free‐radical polymerization processes. II. Tubular reactors
Authors: Zhang Min , Ray W. Harmon 
Published: August 2002

AbstractA tubular reactor model for “living” free‐radical polymerization is developed in this study. The model may be used as a tool to design efficient processes for tailored polymers from “living” free‐radical polymerization. Examples presented include preparing bimodal polymers and copolymers of n‐butyl acrylate and styrene. Residence time distribution effects on polymer properties are investigated by varying the Peclet number, to show the degree of backmixing that adversely affects polymer properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1047–1056, 2002
Multilayered polymer particles. I. Synthesis of hydrophilic poly(dimethyl aminoethyl methacrylate) core particles
Authors: Sangsirimongkolying Ratsamee , Kiatkamjornwong Suda , Damronglerd Somsak , Ma Guang‐Hui , Omi Shinzo 
Published: August 2002

AbstractHydrophilic poly(dimethyl aminoethyl methacrylate) (PDMAEMA) copolymer was obtained by suspension polymerization using 2,2′‐azobisisobutyronitrile as an initiator, and by emulsion polymerization using 2,2′‐azobis(2‐amidinopropane)·2HCl (V‐50). The influences of reaction parameters on the particle size and size distribution were investigated. For suspension polymerization, these included the concentrations of ethylene glycol dimethacrylate (EGDMA) crosslinking agent, ethyl acetate (EA), and Na2SO4 electrolyte, the types of comonomer [methyl methacrylate (MMA) or styrene (ST)], solvent (EA or acetone), and stabilizer [poly(oxyethylene nonylphenylether) with 23 units of ethylene oxide (PEO23) or polyvinylpyrrolidone K30 (PVP)], polymerization temperature, and ST content in the comonomer feed. For the emulsion polymerization, the reaction parameters included the concentration of cetyltrimethyl ammonium chloride and V‐50, and types of initiator [V‐50 or potassium persulfate] and crosslinking agent [EGDMA or divinylbenzene]. The solubility of hydrophilic comonomers in the aqueous phase was a key factor for the stability and morphology of the PDMAEMA particles. It was found that the stable uncrosslinked PDMAEMA latex could be prepared by charging 20 wt % (based on the monomer) of ST. Moreover, the crosslinking agent significantly affected the coagulum in both the suspension and the emulsion polymerizations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1057–1070, 2002
Miscibility and thermal properties of blends of polystyrene with poly(5‐benzoyl‐2,6‐dimethyl‐1,4‐phenylene oxide) or poly(5‐acetyl‐2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Kim Gue‐Hyun , Shin Hack‐Gi , Cho Won‐Jei , Ha Chang‐Sik 
Published: August 2002

AbstractMiscibility and thermal properties of blends of polystyrene (PS) with poly(5‐benzoyl‐2,6‐dimethyl‐1,4‐phenylene oxide) (BPPO) or poly(5‐acetyl‐2,6‐dimethyl‐1,4‐phenylene oxide) (APPO) were investigated using light scattering, FTIR spectroscopy, and thermogravimetric analysis. The optical clarity and light‐scattering behavior showed that both BPPO/PS blends and APPO/PS blends cast from chloroform were miscible over the entire composition ranges in part because of the van der Waals interaction between the component polymers. The light‐scattering studies showed that the miscibility of the APPO/PS blend is better than that of the BPPO/PS blend. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1071–1076, 2002
Preparation and characterization of bioadhesive grafted starch copolymers as platforms for controlled drug delivery
Authors: Geresh Shimona , Gilboa Ygal , Peisahov‐Korol Julia , Gdalevsky Garik , Voorspoels Jody , Remon J. P. , Kost Joseph 
Published: August 2002

Abstract60Co‐gamma‐radiation and ceric ammonium nitrate (CAN) redox‐induced graft polymerization of acrylic monomers (acrylonitrile, acrylic acid, and methyl acrylate) to starch was performed to produce drug‐delivery systems. The grafted starches obtained mainly by redox‐induced polymerization were characterized by chemical and physicochemical methods, and the nature and size of the polyacrylic moiety grafted to the starch were determined. Although the choice of grafting method depended in part on the particular monomer, only copolymers obtained by gamma radiation proved to be satisfactory drug delivery systems. Changes of parameters in the gamma radiation–induced polymerization, such as radiation times and changes in the amount of starch and/or acrylic monomers, were tested in terms of the release rate of model drug compounds. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1157–1162, 2002
Inverted emulsion cast electrically conducting polyaniline–polystyrene blends
Authors: Rao Palle Swapna , Sathyanarayana D. N. 
Published: August 2002

AbstractAn inverted emulsion method for the synthesis of electrically conductive polyaniline–polystyrene blends of different compositions (10, 30, 50, 70, and 85%, wt/wt) is described. Polymerization of aniline is carried out in chloroform in the dispersed phase by using benzoyl peroxide as a novel oxidant and sulfosalicylic acid as the dopant. The blends synthesized with benzoyl peroxide as the oxidant are of high purity and the excess benzoyl peroxide is readily removed with acetone, which is used to break the emulsion and precipitate the polymer. The absorption spectra, FTIR, FT Raman, and electron paramagnetic resonance spectroscopy confirm the presence of polyaniline in the salt form and polystyrene in the blend. The thermal stability of polyaniline salt decreases with an increase in polystyrene content in the blend. The SEM studies show that the particles of polyaniline–sulfosalicylic acid are dispersed on the polystyrene surface. The blends of polyaniline–polystyrene prepared by the present method were found to display conductivities as high as 0.5–0.1 S cm−1. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1163–1171, 2002
A water‐developable negative photoresist based on the photocrosslinking of N‐phenylamide groups with reduced environmental impact
Authors: Chae Kyu Ho , Sun Gum Ju , Kang Jin Koo , Kim Taek Hyeon 
Published: August 2002

AbstractA water‐developable negative photoresist based on the photocrosslinking of N‐phenylamide groups was prepared by the copolymerization of 4‐styrenesulfonic acid sodium salts (SSS) with N‐phenylmethacrylamide (copolymer A) or p‐hydroxy‐N‐phenylmethacrylamide (copolymer B), and its properties such as solubility changes, photochemical reaction, and photoresist characteristics were studied. The copolymer containing a relatively higher amount of SSS units was soluble in water. Solubility changes of the copolymers in the various buffer solutions of pH 4 ∼ 11 and in water upon irradiation were observed by the measurement of insoluble fraction. The copolymers were soluble in water before irradiation, whereas they became insoluble upon irradiation with the UV light of 254 nm. The photochemical reaction of the copolymer studied by the UV and IR absorption spectroscopies indicated that a photo‐Fries rearrangement was favored for copolymer A, whereas a photocrosslinking reaction was predominate for copolymer B. Resist properties of the copolymers were studied by measurement of the normalized thickness and by development of the micropattern. Negative tone images with a resolution of 1 μm were obtained with these materials that have a sensitivity (D) of ∼ 1100 mJ/cm2 with an aqueous developing process.© 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1172–1180, 2002
Production of antimicrobially active silk proteins by use of metal‐containing dyestuffs
Authors: Tsukada Masuhiro , Katoh Hiroshi , Wilson Donna , Shin Bong‐Seob , Arai Takayuki , Murakami Ritsuko , Freddi Giuliano 
Published: August 2002

AbstractThe work presented here discusses a new technique for preparing silk fibers and films with persistent antimicrobial activity through use of metallic dyestuffs during the fiber dyeing process. The length of the silk fibers investigated contracted when the fibers were immersed in concentrated neutral salt solutions, such as calcium or potassium nitrate, at elevated temperature levels. The birefringence and molecular orientation of the silk fibroin molecules became less ordered by the action of the neutral salt solutions, resulting in increased dyestuff absorption. Subsequently, contracted silk fibers were dyed with metallic dyestuffs containing Cr or Cu for the purpose of obtaining silk fibers with antimicrobial activity. Silk fibers dyed with metallic dyestuffs showed significant antimicrobial activity against the plant pathogen Cornebacterium and the human pathogen Coli bacillus. Tensile strength of the silk fibers after the salt shrinking and dyeing processes did not show a significant change, whereas the elongation at break was increased slightly. The techniques described here for preparing significantly active antimicrobial silk fibers are effective and economic ways of providing new materials for industrial and biomedical applications. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1181–1188, 2002
Gelatin/montmorillonite hybrid nanocomposite. I. Preparation and properties
Authors: Zheng Jun Ping , Li Ping , Ma Ya Lu , Yao Kang De 
Published: August 2002

AbstractGelatin/montmorillonite (MMT) hybrid nanocomposite was directly prepared with unmodified MMT and gelatin aqueous solution. Thermal and mechanical properties of the composite were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests. The results indicated that an intercalated or partially exfoliated nanocomposite could be achieved, and the properties of the composite were significantly improved. A Tg peak of high temperature disappeared in the DSC curve of the composite, and the thermogravity and thermally decomposed rate decreased obviously. The tensile strength and Young's modulus were also improved notably, which varied with MMT content, as well as the pH of gelatin matrix. Meanwhile, SEM photographs showed a plasticizing trend of gelatin fracture surface due to intercalation with MMT. Furthermore, the wet mechanical behavior was initially studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1189–1194, 2002
Preparation of microporous chlorinated poly(vinyl chloride) membrane in fabric and the characterization of their pore sizes and pore‐size distributions
Authors: Kang Jong Seok , Kim Ki Yoen , Lee Young Moo 
Published: August 2002

AbstractChlorinated poly(vinyl chloride) (CPVC)/poly(vinyl pyrrolidone) (PVP) membranes were prepared by using the solvent system tetrahydrofuran (THF)/n‐butyl alcohol (n‐BA) to investigate the possibility of pore size and pore‐size distribution control. The coagulation of CPVC/PVP solution was induced by the exposure to water vapor at 25 (±0.5)°C. The average pore diameter, dp, and the size distribution of pores on the surface of the membrane were quantified through the image analyzer from the images visualized by field emission scanning electron microscope (FE‐SEM). Surface pore size and distribution of the prepared CPVC/PVP membrane were strongly affected by the relative humidity (RH) in the environment and the content of PVP used as an additive. Particularly, in the case of CPVC membrane without PVP, the mean pore size was 0.15–0.2 μm, depending on the RH. The pore distribution became broad with the increase of the RH. The membranes had open pores as confirmed by the hydraulic permeation experiment. In addition, the water flux and membrane resistance (Rm) were greatly affected by the composition of polymer solution and the RH. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1195–1202, 2002
Enhancement of the high‐temperature properties of an SEBS thermoplastic elastomer by chemical modification
Authors: Wright Timothy , Jones Allan S. , James Harwood H. 
Published: August 2002

AbstractA procedure was developed for benzoylating the polystyrene segments in polystyrene‐b‐poly(ethylene‐co‐butene)‐b‐polystyrene (SEBS) triblock copolymers. The products were characterized by NMR spectroscopy, gel permeation chromatography, dynamic mechanical thermal analysis, and membrane osmometry. The mechanical properties of the parent and benzoylated copolymers, measured from 25 to 150°C, indicated that benzoylation increases the utility of the polymers at elevated temperatures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1203–1210, 2002
Melting behavior and surface morphology of poly(vinyl acetate‐co‐vinyl alcohol) copolymer
Authors: Thombre Sunita 
Published: August 2002

AbstractIn a study of the surface morphology of commercial poly(vinyl acetate‐co‐vinyl alcohol) (ACA copolymer) with different percents of hydrolysis, different structures like fibrils, spherulites, micelles, vesicles, and spheroids were seen. The copolymer was crystallized by annealing at two different temperatures. The morphology of the polymer after crystallization and also without crystallization was studied. A decrease in the melting temperature just by heating to the melting temperature was observed, and for a detailed study, repetitive heating of the copolymer was carried out and changes in the mass and heat of fusion after every heating was recorded. The morphology of the copolymer after repetitive heating was studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1211–1218, 2002
UV polarizers based on oriented poly(vinyl alcohol)–Chrysophenine–Congo red blend films
Authors: Beekman Elissa , Kocher Christoph , Kokil Akshay , Zimmermann Sven , Weder Christoph 
Published: August 2002

AbstractThe availability of efficient low‐cost ultraviolet (UV) film polarizers is of vital importance to a number of applications, which rely on the use of polarized light in the near‐UV regime. We describe here the preparation of such elements based on stretch‐oriented films comprising poly(vinyl alcohol) and a combination of two commercially available azo dyes, Congo Red and Chrysophenine. Films of various dye contents were prepared and oriented by uniaxial tensile deformation. Moderately stretched films (draw ratio l/l0 = 4–8) exhibit a pronounced optical dichroism, characterized by a polarizing efficiency up to 0.98 at a wavelength of 365 nm. Initial experiments suggest that, even under rather harsh irradiation conditions and without any packaging, these azo‐dye‐based polarizers are surprisingly inert under simulated operating conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1235–1239, 2002
Preparation of poly(vinyl alcohol) films with promising physical properties in comparison with commercial polyethylene film
Authors: Abd El‐Kader K. A. M. , Abdel Hamied S. F. 
Published: August 2002

AbstractPoly(vinyl alcohol) (PVA) films with different thicknesses (0.08, 0.2, 0.23, 0.42 mm) were prepared by a casting technique. The transmission and the absorption of the PVA films were measured as functions of the wavelengths. PVA film with a thickness of 0.42 mm showed zero transmission in the wavelength range of 190–350 nm. The transmission spectrum of a commercial polyethylene film with a thickness of 0.21 mm was compared to the transmission spectrum of PVA film with a thickness of 0.42 mm. A correlation was found between the two transmission spectra in the region 190–350 nm and a 20% increase in the transmission of the PVA film in comparison with the transmission of commercial polyethylene in the region 350–1500 nm. The near‐infrared region of the transmission of commercial polyethylene was increased by 15% with respect to the transmission of the PVA film. The stress–strain measurements were done for PVA and commercial polyethylene films. The Young's modulus and the strength at break for PVA films are higher by two orders of magnitude than those for commercial polyethylene film. The strain at break for commercial polyethylene is 17% lower than that for PVA film. Radiation effects on the optical properties of PVA and commercial polyethylene films were investigated. The PVA and commercial polyethylene films were irradiated with a xeon arc lamp at 3.5–5 W/cm2. The optical properties for PVA and commercial polyethylene films were studied after irradiation. The obtained results showed that PVA film with a thickness of 0.42 mm gave promising properties which could be used in technological applications. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1219–1226, 2002