bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nylon‐6 film grafted with acrylic acid for dissepiment in alkaline storage batteries
Authors: Liu Minying , Zhao Qingxiang , Wang Yudong , Niu Junfeng , Cao Shaokui 
Published: February 2004

AbstractA grafted nylon‐6 membrane that can be used in alkaline storage batteries was prepared by grafting acrylic acid onto nylon‐6 film using (NH4)2Ce(NO3)6/H2SO4 as initiator. The nylon‐6 films to be grafted were pre‐swelled in 20% formic acid solution, activated with an aqueous solution containing ceric ammonium nitrate and sulfuric acid. The grafting efficiency was greatly affected by the reaction temperature, the concentration of (NH4)2Ce(NO3)6/H2SO4, and the swelling time in formic acid. The degree of grafting that could be achieved under optimized conditions was up to 312%. Through infrared spectroscopy (IR) and X‐ray photoelectron spectroscopy (XPS) analysis, it was realized that graft reaction took place on the nitrogen atom of the amide group and the density of grafting point increased with an increase in the degree of grafting in a certain range. The highest density of grafting point was found to be 51.3% in a given set of reaction conditions. X‐ray diffraction illustrated that the crystallinity of the grafted membranes decreases with the increase of the degree of grafting. A membrane with 173% degree of grafting showed electric resistance of 0.11 Ω/cm2, and ion exchange capacity (IEC) of 8.7 mmol/g, which can meet the requirement for the electric discharge of storage batteries with strong power. Copyright © 2004 John Wiley & Sons, Ltd.
Fluorescence from fluorescent dye‐based polyurethane ionomer(II)
Authors: Wang C. L. , Zhang Z. J. , Kuo Y. M. , Chao D. Y. 
Published: February 2004

AbstractThe reaction of 6‐amino‐2(2‐hydroxy‐2‐phenyl‐ethyl)benzo[de]isoquinoline‐1,3‐dione with toluene diisocyanate and other additives to form the structure of the fluorescent dye‐based polyurethane (PU) ionomer has been proven by infrared (IR) spectroscopy. In aqueous solution, the fluorescence performance for the fluorescent dye‐based PU ionomer molecule appears at 516 nm, and its quantum yield is calculated to be 0.804. It is important to point out that increased concentration of the reactive fluorescent dye employed to prepare the fluorescent dye‐based PU ionomer molecule will not enhance the fluorescence performance of this ionomer molecule. This is probably the result of increased intra molecular interaction between ionomer molecules themselves, which may substantially reduce the excitation of the ionomer molecule by absorbing UV light. However, 6‐amino‐2‐(2‐hydroxy‐2‐phenyl‐ethyl)benzo[de]isoquinoline‐1,3‐dione is considered to be a good fluorescent dye for use in resins. Furthermore, the addition of a reactive fluorescent dye to prepare the fluorescent dye‐based PU ionomer molecule will significantly enhance the tensile strength but, however, will appreciably decrease the elongation of this ionomer molecule. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of well‐defined chain‐end‐functionalized polystyrenes with four, eight, and sixteen perfluorooctyl groups and their surface characterization
Authors: Hirao Akira , Sakai Shiko , Sugiyama Kenji 
Published: February 2004

AbstractWe have successfully synthesized a series of novel well‐defined chain‐end‐functionalized polystyrenes with a definite number of four, eight, and sixteen perfluorooctyl (C8F17) groups, via living anionic polymerization, by the coupling reaction of chain‐end‐functionalized polystyrenes with dendritic benzyl bromide moieties with the functionalized 1,1‐diphenylalkylanion prepared from sec‐BuLi and 1,1‐bis(4‐tert‐butyldimethylsilyloxyphenyl)ethylene, deprotection, and a Williamson reaction with C8F17(CH2)3Br. The resulting polymers were precisely controlled in molecular weight and molecular weight distribution as well as well‐defined in chain‐end‐functionality. Surface structures of the annealed films cast from such chain‐end‐functionalized polystyrenes with C8F17 groups have been characterized by contact angle and angle‐dependent X‐ray photoelectron spectroscopy (XPS) measurements. It has been clearly observed by both measurements that the C8F17 groups are preferentially segregated from their polystyrene main chains and significantly enriched at the surfaces. However, the degree of enrichment of C8F17 group increased only to a small extent by increasing the C8F17 group from four, eight, and even sixteen in number. We have compared the present results with the previous ones obtained by using chain‐end‐functionalized polystyrenes with one, two, three, and four C8F17 groups and the structurally analogous block copolymers and discussed in more detail in terms of the dependence of enrichment degree on number of C8F17 group. Copyright © 2004 John Wiley & Sons, Ltd.
Modification of end‐groups of aliphatic hyperbranched polyester
Authors: Qiu Teng , Tang Liming , Fu Zhiwei , Tuo Xinlin , Li Yi , Liu Deshan , Yang Wantai 
Published: February 2004

AbstractAliphatic hyperbranched polyester (P1) synthesized from 2,2‐bis(methylol)propionic acid and tris(methylol)propane was reacted with phthalic anhydride and trimellitic anhydride to form modified polymers P2 and P3, respectively. The reaction kinetics and the effect of different end‐groups on the polymer properties were studied. Contrast to P1, both P2 and P3 could form global aggregates in dimethylformamide/water mixture due to their amphiphilic structures. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and properties of fluoropolyacrylate coatings
Authors: Tang Liming , Li Yi , Wu Xiaomin , Shan Xiaofeng , Wang Weicheng 
Published: February 2004

AbstractHydroxylic fluoropolyacrylates were prepared by solution copolymerization of styrene (St), 2‐hydroxypropyl acrylate (2‐HPA), butyl acrylate (BA) and fluoroacrylate under various compositions. They were further cured with hexamethylene diisocyanate (HMDI) to obtain hydrophobic coatings under ambient condition. The curing reaction was identified by differential scanning calorimetry (DSC) and gel content analysis. The properties, especially the anti‐frosting performance, of the cured coatings were measured. The results indicated that the anti‐frosting property was improved by the prescence of the hydrophobic coating. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and ionic conductivity of a polysiloxane containing quaternary ammonium groups
Authors: Kang Jun‐Jie , Li Wei‐Ying , Lin Yuan , Li Xue‐Ping , Xiao Xu‐Rui , Fang Shi‐Bi 
Published: February 2004

AbstractA novel quaternary ammonium salt, polysiloxane containing quaternary ammonium groups, was designed and synthesized. Thermogravimetric results showed that the polymer maintained stable below 250°C. Ambient conductivities higher than 10−4 S cm−1 could be observed when appropriate amounts of suitable plasticizers were incorporated into the present quaternary ammonium salt. A dye‐sensitized solar cell fabricated using a plasticized electrolyte showed a fill factor of 0.50 and an energy conversion efficiency of 7.7%. Copyright © 2004 John Wiley & Sons, Ltd.
Study of cobalt(II)‐chitosan coordination polymer and its catalytic activity and selectivity for vinyl monomer polymerization
Authors: Huai‐min Guan , Xian‐su Cheng 
Published: February 2004

AbstractA cobalt(II)‐chitosan coordination polymer has been prepared by soaking a chitosan film in CoCl2 aqueous solution. The results have been investigated by means of X‐ray photoelectron spectroscopy (XPS), Fourier Transform infrared FT‐IR spectroscopy, thermal analysis and electrical conductivity measurements. The XPS and FT‐IR spectra reveal that the chitosan coordinated with cobalt(II) through both oxygen and nitrogen atoms in the chitosan chain. The XPS results show that the coordination polymer possess the same shake‐up peaks with CoCl2, indicating that the cobalt(II)‐chitosan coordination polymer is high spin and the coordination number of cobalt(II) centers is four, and the electrical conductivity measurements confirm this result. Also, cobalt(II) coordination polymer can be used as a catalyst, and the polymerization of vinyl acetate was carried out in the presence of the coordination polymer/Na2SO3/H2O at pH 7 and normal temperature. The polyvinyl acetate possessed a random structure. Copyright © 2004 John Wiley & Sons, Ltd.
Organic emissive materials and devices for photonic communication
Authors: Suzuki Hiroyuki , Yokoo Atsushi , Notomi Masaya 
Published: February 2004

AbstractThis article describes our recent progress on the development of organic emissive materials and devices for photonic communication applications. Luminescence properties in the infrared (IR) region were examined for two types of organic emissive material, an organic rare earth complex and an organic ionic dye, and their potential for use as emissive materials in photonic communication applications was discussed. The luminescence mechanism elucidated in this study suggested a guideline for the future development of organic IR emissive materials. Novel organic emissive devices were fabricated by combining organic emissive materials with various types of photonic crystal structure utilizing nanotechnology. These devices utilize the advantages and unique properties of organic materials, and so signal the way towards the breakthroughs needed to realize emissive devices for the photonic communication networks of the future. Copyright © 2004 John Wiley & Sons, Ltd.
Study on the synthesis and application of salt‐resisting polymeric hydrogels
Authors: Li Yanfeng , Li Xianzhen , Zhou Lincheng , Zhu Xiaoxia , Li Bonian 
Published: February 2004

AbstractA kind of hydrogel of semi‐2 interpenetrating polymer network (IPN) consisting of poly(sodium acrylate) (PSA) and poly(vinyl alcohol) (PVA), i.e. semi‐2 IPN PVA/PSA hydrogel, was synthesized by interpenetrating polymerization of sodium acrylate and N,N′‐methylene bisacrylamide into a solution of PVA, using potassium persulfate and sodium bisulfite as initiators. The synthetic conditions affecting the properties of the resulting hydrogel and optimal conditions were investigated, while the resulting IPN hydrogel used as an agent for holding‐water was employed in the planting of trees in an arid soil containing a higher amount of saline. Experimental results indicate that the semi‐2 IPN PVA/PSA hydrogel has an absorbency of 700–800 and 70–90 ml/g for distilled water and saline solution, respectively, as well as showing a better salt‐resistance and water‐absorbing rate compared to polymeric hydrogels based on PSA due to the introduction of the PVA segment. The results showed the surviving ratio of the planted saplings could reach 100% and be raised to 70% compared with those without hydrogel. Copyright © 2004 John Wiley & Sons, Ltd.
Preparation and catalytic oxidation properties of inorganic polymer encapsulated metal complexes
Authors: Wang Rong‐Min , Zhang Zhen‐Lin , Lou Jian‐Fang , Wang Yun‐Pu , Song Peng‐Fei , Xia Chun‐Gu 
Published: February 2004

AbstractAn inorganic polymer supporter, such as molecular sieve MCM‐41, was used as a support for encapsulating metal complex catalysts. The metal complex was prepared with L‐glutamic acid and Co(OAc)2 · 4H2O. Their catalytic activity in oxidation of cyclohexene with H2O2 was studied. The major products of this reaction were hexanedial, 2‐cyclohexen‐1‐one, 2‐cyclohexen‐1‐hydropenoxide and epoxide, which is different from typical oxidation of cyclohexene. The effect of temperature, solvent, additive, the amount of catalyst and oxidant were also discussed. The catalyst shows high catalytic activity. Copyright © 2004 John Wiley & Sons, Ltd.
Condensation polymers of dicyclopentadienyl iron with aromatic diazoium salts and magnetism
Authors: Chai Chun‐Peng , Wang Yun‐Pu , Wang Rong‐Min , Ren Hong‐Xia , Hao Cheng‐Jun 
Published: February 2004

AbstractFive kinds of condensation polymers of dicyclopentadienyl iron with aromatic diazoium salts were firstly composed. Using inductively coupled plasma (ICP) and FT‐IR their structures were characterized. Their thermal stability was discussed using TG and DTA. The electronic structure of iron was studied by Mössbauer spectra and electron spin resonance (ESR) spectra. Measurement of temperature dependence of the magnetic property (M–T curve) of the condensation polymers indicates that they have stronger magnetism. At a temperature of T = 1.5 K, the loop of magnetic hysteresis was obtained. The strongest magnetic condensation polymer was benzyl ferrocene making 1/χm − T, obtaining a condensation temperature of Tc = 20.5 K, when T < Tc, the condensation polymer shows ferromagnetism. Copyright © 2004 John Wiley & Sons, Ltd.
Hydrogenation of five‐membered heterocycles of polymer‐supported palladium catalyst at normal temperature and pressure
Authors: Guo Zhen , Feng Hua , Ma Heng‐chang , Kang Qiao‐Xiang , Yang Zhi‐Wang 
Published: February 2004

AbstractTo modify the surface of aminomethyl polystyrene, grafting of hyperbranched dendritic polyamidoamine, a new class of topological macromolecules, onto the surface was investigated. It was found that hyperbranched dendritic polyamidoamine was propagated from aminomethyl polystyrene surface by repeating two processes: (1) Michael addition; (2) amidation. Furthermore, salicylal (SA) readily postgrafted to the hyperbranched dendritic polyamidoamine‐grafted‐aminomethyl polystyrene. Finally, catalytic hydrogenations of pyrrole, furan and thiophene were investigated by the modifying polyamidoamine‐grafted aminomethyl polystyrene with SA (MPGAPS)‐supported palladium catalyst. The double‐bond of the ring was hydrogenated to single‐bond ring of tetrahydro‐compound at first, then the ring is broken directly. In general, these reactions were degradation under reduction. UV absorbance spectroscopy, gas chromatography (GC), and power of hydrogen (PH) detection were used to analyze the reactants and products, and infrared (IR), X‐ray photoelectron spectroscopy (XPS) and inductively coupled plasma‐atomic emission spectrometry (ICP‐AES) characterized the catalyst. Copyright © 2004 John Wiley & Sons, Ltd.
Preparation of a multifunctional bacterial fertilizer by living azospirillum simplex cells immobilized on poly(sodium acrylate)
Authors: Wang Yun‐Pu , Chen Na‐Li , Wang Rong‐Min , Xiong Yu‐Bing , Zha Rui‐Tao 
Published: February 2004

AbstractA living azospirillum simplex cell (LASSC) was immobilized on poly(sodium acrylate) (PSA). The method of preparation of the immobilized‐cell (LASSC‐PSA) was studied. LASSC was immobilized on PSA in an immobilizing medium of Na2HPO4 · 12H2O‐NaH2PO4 · 2H2O (pH 7.0) buffer, sterile water, a solution of NaCl (0.85% m/m), cultured medium (pH 7.0), respectively. The desorption capacity of LASSC on LASSC‐PSA in sterile water was measured and when the Na2HPO4 · 12H2O‐NaH2PO4 · 2H2O (pH 7.0) buffer served as the immobilizing medium, the desorption capacity of LASSC on LASSC‐PSA was the highest. The rate (m/m) of PSA and LASSC (wet weight) also affected considerably the desorption capacity of LASSC on LASSC‐PSA in sterile water, and the best rate was 1 : 0.5. The desorption capacity of LASSC on LASSC‐PSA was 50% of that at the beginning and that was still 109 cfu/g on storage for 5 months when the rate (m/m) of PSA and LASSC (wet weight) was 1 : 0.5, using Na2HPO4 · 12H2O‐NaH2PO4 · 2H2O (pH 7.0) buffer as immobilizing medium. Copyright © 2004 John Wiley & Sons, Ltd.
Preparation and adsorption properties of modified chitosan
Authors: Wang Rong‐Min , Xie Xin , Wang Jin‐Qing , Pan Su‐Juan , Wang Yun‐Pu , Xia Chun‐Gu 
Published: February 2004

AbstractChitosan has been modified by polyacrylate sodium or acrylate sodium in the presence of glutaraldehyde, which afforded four kinds of modified chitosan (CTS‐PA) with different ratios of reacting substance. They are used as an environmentally benign polymer adsorbent. The adsorption properties of these CTS‐PA to Pb2+ have been measured. The best adsorption to Pb2+ was CTS‐PA4, the removal efficiency was higher in higher concentration solution than in a lower one, the value of the removal efficiency is approximate 99.991%. Copyright © 2004 John Wiley & Sons, Ltd.
Studies of waterborne emulsion of chemically modified epoxy resin
Authors: Zhang Zhaoying , Huang Yuhui , Liao Bing , Cong Guangmin 
Published: February 2004

AbstractThe bisphenol‐A type epoxy resin was modified by p‐aminobenzoic acid. The modified resins were characterized using IR spectroscopy and differential scanning calorimetry (DSC). The progress of emulsification process was characterized by measuring the variations of conductivity and viscosity while dropping water into the modified resin solution. The factors influencing the emulsion particle size of the waterborne coating films of the modified resins were investigated. Copyright © 2004 John Wiley & Sons, Ltd.
A novel hyperbranched conjugated polymer for light emitting devices
Authors: He Qingguo , Huang Hongmin , Sun Qingjiang , Lin Hongzhen , Yang Junlin , Bai Fenglian 
Published: February 2004

AbstractA novel hyperbranched conjugated polymer with benzene as core, phenylene vinylene as connecting groups and dimethylamino benzene as end groups (DMA‐HPV) was synthesized and characterized. It shows excellent solubility, film‐forming ability and very high thermal stability Tg = 255°C, TID = 398°C). Its fluorescence quantum efficiency in film is almost as large as that in solution (∼50%). The light emitting diodes and the light emitting cells were fabricated. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and photophysical properties of a novel semiconducting polymer
Authors: Huang Hongmin , He Qingguo , Lin Hongzhen , Bai Fenglian , Sun Zhi , Li Qingshan 
Published: February 2004

AbstractAn alternating copolymer containing triphenylamine (TPA) and cyano‐substituted benzene moieties, TPA‐CNPPV was synthesized using the Wittig reaction. The monomers and polymer were characterized by H‐NMR, FT‐IR and mass spectroscopy (MS). The polymer shows good solubility in common organic solvents and excellent film‐forming ability. Thermogravimetric analysis (TGA) demonstrates that the polymer has a degradation temperature (TD) of 600°C; differential scanning calorimetry (DSC) result indicates that the glass transition temperature (Tg) of TPA‐CNPPV is 160°C, suggesting high thermal stability. The photophysical properties of the light‐emitting material were investigated in both solution and spin‐coated film. Photo‐isomerization of the polymer was investigated by UV‐vis and fluorescence spectra. The interaction between TPA‐CNPPV and C60 was studied by fluorescence quenching. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and characterization of a copolymer containing 1,1′‐binaphthyl‐2,2′‐diamino and carbazolyl units
Authors: Zhang Caihong , Chen Zhaobin , Bai Fenglian 
Published: February 2004

AbstractA novel copolymer has been synthesized by copolymerization of 2,2′‐dimethacrylamido‐1,1′‐binaphthyl (DMBN) with vinylcarbazole (VCZ) and its fluorescence characterization has been studied. The results show that the copolymer (DMBN‐VCZ) is soluble in some common organic solvents and the fluorescence of the copolymer (DMBN‐VCZ) can be quenched by both electron donors and electron acceptors where the quenching effects follow the Stern–Volmer equation. The dimolecular exciplexes between copolymer (DMBN‐VCZ) and strong electron donor or electron acceptor are formed. Moreover, the interaction between copolymer (DMBN‐VCZ) and C60 is also studied by fluorescent quenching. Copyright © 2004 John Wiley & Sons, Ltd.
Design and synthesis of functional polymers by in vitro selection
Authors: Ito Yoshihiro 
Published: February 2004

AbstractCombinatorial chemistry, in which targeting molecules are selected from a random molecular library, has recently developed. Among the methods devised by combinatorial chemistry, the recent progress in functional polymers that have molecular recognition ability and catalysis ability, and in bio‐device polymers based on these functionalities is reviewed. Copyright © 2004 John Wiley & Sons, Ltd.
First hyperpolarizabilities of triazine derivatives. Ab initio studies and Hammett correlation
Authors: Park Gyoosoon , Cho Bong Rae 
Published: February 2004

AbstractFirst hyperpolarizabilities (β) of triazine derivatives were studied by the ab initio method (HF/6–31G). The β values of these molecules increase with a stronger donor and as the conjugation length increases, probably because the electronic charge becomes more delocalized and the HOMO–LUMO energy gap (ΔE) and the bond length alternation (BLA) decrease with variation of the chromophore structure. Also, the susceptibility of β to the donor strength is found to be larger for a more elongated substrate. Noteworthy is the excellent linear relationship between β and BLA and also the gas‐phase substituent constants (σ+gas). This result may serve as a useful guideline for the design of two‐dimensional octupoles with large first hyperpolarizabilities. Copyright © 2004 John Wiley & Sons, Ltd.
Regio‐ and stereochemistry of Michael addition of methanol to Thiele's ester
Authors: Minter David E. , Smith William B. , Marchand Alan P. , Etukala Jagan Reddy , Sivappa Rasapalli 
Published: February 2004

AbstractAcid‐promoted esterification of Thiele's acid with methanol was found to afford three products. In addition to the expected major product (i.e. the corresponding dimethyl ester, 2a), two minor products are obtained, one of which, 3, results from subsequent Michael addition of methanol to the norbornene CC double bond in 2a. Analysis of its one‐ and two‐dimensional NMR spectra indicates that this minor product possesses structure 3a in which the (C‐5)—OCH3 and (C‐6)—CO2CH3 bonds are exo and endo, respectively. This conclusion is reinforced by the results of thermodynamics calculations and associated chemical shift calculations. In addition, theoretical analysis of competing transition states for Michael addition of methanol to 2a suggests that exo approach of methanol towards the (C‐5)(C‐6) double bond in the substrate is preferred kinetically over the corresponding endo reaction pathway. Copyright © 2004 John Wiley & Sons, Ltd.
Specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions in aqueous media
Authors: Mubofu Egid B. , Engberts Jan B. F. N. 
Published: February 2004

AbstractA comparative study of specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas hydrochloric acid was employed for specific acid catalysis. At equimolar amounts of copper(II) nitrate and hydrochloric acid (0.01 M, for example) and under the same reaction conditions, the reaction rate for 1a with 2 is about 40 times faster with copper catalysis than with specific acid catalysis. Moreover, at 32°C and 0.01 M HCl, the reaction of 1b with 2 is about 21 times faster than the same uncatalyzed reaction in pure water under the same reaction conditions. The inverse solvent kinetic isotope effect shows that these Diels–Alder reactions undergo specific acid catalysis. Copyright © 2004 John Wiley & Sons, Ltd.