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Table of Content

    24 September 2003, Volume 24 Issue 9
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    Articles
    Thermal Decomposition of Microporous Aluminophosphate AlPO4-HDA
    XIAO Li-Ping, XU Ru-Ren
    2003, 24(9):  1537-1540. 
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    Thermal decomposition of microporous aluminophosphate AlPO4-HDA has been investigated by using thermogravimetric-differential thermal analysis coupled with mass spectrometry(TG-DTA-MS), X-ray diffraction(XRD), Fourier transform infrared (FTIR) and solid-state MAS NMR spectroscopy. The results show that the template decomposition involves three steps. First, the H-bondings between the inorganic framework and the template are broken; then, the template undergoes sequential Hofmann degradation reactions followed by β-eliminations and oxidations; finally, the remaining organic components are removed at a high temperature. The results obtained by using MAS NMR indicate that there is a change in the coordination state of certain framework Al and Pwith the partial removal of the template.
    Luminescence Property of La2CaB10O19:Ce3+in VUV-Vis Range
    HE Hong, LIANG Hong-Bin, TAO Ye, WANG Shu-Bin, SU Qiang
    2003, 24(9):  1541-1543. 
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    The excitation and emission spectra of La2CaB10O19: Ce3+in VUV-Vis range were investigated. Three bands peaking at 307, 330 and 356 nm in emission spectrum and six bands peaking at 194, 224, 243, 260, 274 and 318 nm in excitation spectra are observed. This fact indicates that Ce3+ions occupy two kinds of lattice sites in La2CaB10O19, one kind is substituted for La3+with coordination number ten and the other is substituted for Ca2+with coordination number eight. This result is consistent with that of La2CaB10O19: Eu3+. When Eu3+is used as a structural probe, two 5D0→7F0transitions peaking at 576. 8 and 578. 8 nm are observed in the emission spectrum. This indicates that Eu3+ions also occupy two kinds of lattice sites in La2CaB10O19.The broad band peaking at 162 nm can be attributed to the host absorption, and the charge transition band(CTB) of O2-→Ce3+may be obscured in this broad band.
    Synthesis and Characterization of Sb Doped SnO2(ATO) Nanoparticles
    ZHANG Jian-Rong, GAO Lian
    2003, 24(9):  1544-1547. 
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    Sb doped SnO2(ATO) nanoparticles were synthesized by the coprecipitation method with Sn and Sb2O3as the raw materials. TG-DSC curves showed that the precursors lose weight completely before 450℃; FTIRspectra showed that the precursors convert to SnO2at 450℃; X-ray powder diffraction patterns of the powders indicated the same rutile lattice structure known from bulk SnO2.The size of the particles calcinated at 500 ℃ was about 12 nm. The size of the nanocrystalline powders increased with the calcination temperature increasing. TEM showed that the particles are weakly agglomerated. The powders showed better sintering behavior and the density is about 97. 3% when being sintered at 950 ℃ for 5 h. The resistivity determined by the Hall system indicated that the particles are greatly conductive.
    Synthesis and Photoelectric Property of Complexes η2-C60[Ru(NO)(PPh3)]n
    DONG Zhen-Rong, CHENG Da-Dian, WU Zhen-Yi, YANG Sen-Gen, LIN Yong-Sheng, ZHAN Meng-Xiong
    2003, 24(9):  1548-1551. 
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    The fullerene complexes, η2-C60[Ru(NO)(PPh3)]n, were prepared by the reaction of C60with Ru(NO)2(PPh3)2under a nitrogen atmosphere and refluxing. The new complexes were characterized by means of elemental analysis, IR, XPS, electronic spectra, 31PNMR and 13CNMR. The results show that the η2form complexes can be formed by C60bonding to Ru(NO)2(PPh3)2in the σ-π way and there is hy-perconjugation effect in the molecule. So electrons will flow easier and photoelectric properties for the new compounds are expected. In addition, the structures of the complexes were supposed. The ruthenium is 4-coordinated in the complexes, bonding to two carbon atoms, one PPh3and one NO. The photoelectric effect of the fullerene complexes was also studied. The results show that the photoelectric properties of the fullerene complexes are better than those of pure GaAs electrode, and is related to thickness of the sample film, the media and the number of the bonded organometallic groups.
    Synthesis,Structure and Dielectric Properties of a New Pervoskite-related Niobate Ba3La2Ti2Nb2O15
    ZHANG Hui, FANG Liang, HONG Xue-Kun, MENG Fan-Cheng, LIU Han-Xing, YUAN Run-Zhang
    2003, 24(9):  1552-1554. 
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    A new niobate Ba3La2Ti2Nb2O15was synthesized by high temperature solid state reaction in the BaO-La2O3-TiO2-Nb2O5system. The chemical compositions, crystal structure, microstructure, density and melting point of the new compound were characterized by EPMA, XRD, SEM, DTA and so on. Ba3La2Ti2Nb2O15crystallizes in the hexagonal system with unit cell parameters a=0. 5682(1) nm, c=-1.1657(1) nm, and space group P3 m1, Z=l. The structure may be described as four (Nb,Ti)O6octa-hedra corner-sharing to form hexagonal perovskite layer, while Ba or La occupying the interstices. The Ba3La2Ti2Nb2O15ceramic exhibits a high dielectric constant of 90. 04, a low dielectric loss of 4. 5 × 10-4and a small temperature coefficient of dielectric constant of -65 × 10-6K-1at 1 MHz due to its close structure and relative high dielectric polarizabilities of Ba2+, La3+, Ti4+and Nb5+. Ba3La2Ti2Nb2O15might be a suitable candidate of high er microwave dielectric ceramics.
    Synthesis and Structure of a New Open Metal-organic-inorganic Hybrid Framework [Sn(SO4)(BDC)(H2O)](BDC=Terephthalic acid)
    SUN Jin-Yu, ZHOU Ya-Ming, CHEN Zhen-Xia, TU Bo, WENG Lin-Hong, ZHAO Dong-Yuan
    2003, 24(9):  1555-1557. 
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    Anew coordination polymer [Sn(SO4)(BDC)(H2O)](BDC=terephthalic acid) with two dimensional (2D) open metal-organic-inganic hybrid framework structure has solvothermally prepared in N, N-dimethylformamide solution at 160℃. The structure determined from X-ray single crystal diffraction has space group P21of monoclinic system with a=0. 6816(5),b=1. 7628(14), c=0. 7722(6) nm, β=103. 7°, V=0. 9012(12) nm3, Z=4, Dc= l. 569 Mg/m3; R1= 0. 0514[I>2σ(I)], Rw=0.1381. The product is characteristic of 2D channels with 2D wavy layer structure.
    Synthesis and Crystal Structure of Organic-inorganic Hybrid:{[Na2(H2O)4]2[γ-Mo8O26(Gly-Gly)2]}·4H2O
    HAN Zheng-Bo, AN Hai-Yan, WANG Li, LUAN Guo-You, WANG En-Bo, HAN Zheng-Xue
    2003, 24(9):  1558-1560. 
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    A new compound, {[Na2(H2O)4]2[γ-Mo8O26(Gly-Gly)2]}·4H2O, was synthesized and characterized by elemental analyses, IRand single crystal X-ray diffraction. The compound crystallizes with triclinic symmetry in the space group P1 with a=0. 94166(9) nm, b=1. 13098(8) nm, c=1. 17804 (8) nm, α=63. 768(6)°,β=74. 231(5)°, γ=82. 402(6)°, V=1. 08294(15) nm3, Z=1, R1= 0. 0329, wR2= 0. 0925. The Gly-Gly ligands are coordinated via their carboxylate-oxyyen atoms at the vacant sites on the two five-coordinate molybdate for the centrosymmetric γ-[Mo8O26]]4-anion. Because of weak interaction between the unit of γ-[Mo8O26(Gly-Gly)2] and [Na2(H2O)4] unit, one infinite 2D layer can be constructed.
    Direct Electrochemistry of Hemoglobin Immobilized on Carbon Paste Electrode by Inorganic Film
    WANG Quan-Lin, YANG Bao-Jun, LU Gong-Xuan
    2003, 24(9):  1561-1566. 
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    Direct electrochemical behavior of hemoglobin (Hb) immobilized on carbon paste electrodes by Sol-gel film derived from tetraethylorthosilicate was investigated for the first time. Hb-Sol-gel-modified electrodes showed a pair of well-defined and nearly reversible cyclic voltammetric peaks for HbFe(Ⅲ)/ Fe( Ⅱ ) redox couple at about -0. 275 V(vs. Ag/AgCl) in pH 7. 0 phosphate buffers. The formal potential of Hb heme Fe( Ⅲ )/Fe(Ⅱ) couple shifted linearly between pH5. 0-11. 0 with a slope of 51. 85 mV/ pH, suggesting that one proton was coupled to each electron transfer in the electrochemical reaction. It was demonstrated by FTIR spectra that the structure of Hb was still maintained native-like in the film. The immobilized Hb displayed the features of a peroxidase and gave an excellent electrocatalytic response to the reduction of H2O2 Consequently, this work provides a possible route of using Hb-Sol-gel-modified electrodes as the third generation biosensors.
    Potentiometric Determination of Formation Constants of Complex of Calix[6]arene Ester with Metal Ions in Solvent Polymeric Membrane with Two-layer Sandwich Membrane Electrode
    DI Xiao-Wei, HE Xi-Wen
    2003, 24(9):  1567-1571. 
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    Atwo-layer sandwich membrane was used as the indicator electrode to determine the formation constants of the complexes of tert-butyl-calix[6]arene hexaacetic acid hexaethyl ester with metal ions in solvent polymeric membrane potentiometrically. Anew method for the measurement of sandwich membrane potential from which the formation constant of the complex can be calculated was proposed. Calix[6]arene ester was used as ionophore and the complex formation constants of it with Li+, Na+, K+, Cs+and NH4+were determined. The logarithmic values of the formation constants were found to be 6. 14, 6. 48, 6. 74, 7. 43 and 6. 21 respectively. According to the experimental data, Cs+was chosen as the primary ion because of its highest value of complex formation constant and a Cs-selective electrode was prepared. The resulting logarithmic selectivity coefficients to the ions of Li+, Na+, K+and NH4+are found to be -3. 33, -2. 54, -1. 60 and - 2. 90 respectively by fixing interference method (FIM). From the data of both formation constants and selectivity coefficients, a good correlation between them was found. The higher the formation constant of the complex of calix[6]arene ester with the responded ion is, the higher the selectivity to it is.
    Resolution of Chemical Reaction Process with Unknown Kinetic Model
    ZHU Zhong-Liang, ZHAO Yi, CHENG Wen-Zhi, LI Tong-Hua
    2003, 24(9):  1572-1576. 
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    Iterative target transformation factor analysis was applied to resolve the kinetic-spectral data matrix monitored in the process of spectroscopic reaction of unknown kinetic model and the kinetic spectrum of each component is obtained. Anovel approach was proposed to estimate the initial vectors based on the spectral features such as the isoabsorptive point of the relative component in the system. With the proposed approach, the simulated data matrix for a two-step consecutive reaction in which every component had absorption were successfully resolved. The data matrix measured in the electrodegradation process of salicylic acid, in which the final product has no absorption, can also be resolved with a satisfying result.
    Studies on Oligosaccharides from Acanthopanax Senticosus Harms (AS) by Electrospray Ionization Tandem Mass Spectrometry(MSn)
    GUO Ming-Quan, SONG Feng-Rui, CHEN Mao-Lian, BAI Yu, LIU Zhi-Qiang, LIU Shu-Ying
    2003, 24(9):  1577-1581. 
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    Aseries of oligosaccharide mixtures from extracts of Acanthopanax senticosus Harms(AS) were determined in both the positive ion mode and negative ion mode of electrospray ionization tandem mass spectrometry. In the positive ion mode, the ions observed are characteristic of cluster ions with a mass difference of 16, and they are considered as the alkali adducts of [M+Na]+/[M+K]+or [M+H2O+Na]+/[M+H2O+K]+. In the negative ion mode, the ions observed are deprotonated oligosaccharides like [M-H]-or [M+H2O-H]-. MS" experiments of trisaccharides were performed in both the positive and negative ion modes to highlight the application of ESI-MSnto the structure analyses of oligosaccharides.
    Single Cell Injection and Lysis on a Microfluidic Chip
    GAO Jian, YIN Xue-Feng, FANG Zhao-Lun, XIA Fang-Quan
    2003, 24(9):  1582-1584. 
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    A microfluidic system was developed for the analysis of single biological cells, with functional integration of cell sampling, single cell loading, docking, lysing, and capillary electrophoretic separation in microfabricated channels on a single glass chip. Channels were 12 μm deep and 75μm wide, with a double-Tdesign cell injector that was directly connected to a capillary electrophoretic separation channel with an effective separation length of 37 mm. During sampling with a cell suspension (cell population 1. 2×105cells/mLin physiological salt solution), differential hydrostatic pressure (created by adjusting liquid levels in the four reservoirs) was used to control cell flow exclusively through the 200 μm channel between the two T-junctions. Single cell loading into the separation channel was achieved by electrophoretic means by applying a set of potentials at the four reservoirs, counteracting the hydrostatic flow. Aspecial docking (adhering) procedure for the loaded cell was applied through flow control to affect cell lysis at the applied CE separation voltage(1. 4 kV) within the working electrolyte(pH 9. 2 borate buffer) without additional lysates. The docked lysing approach reduced dispersion of released intracellular constituents, and significantly improved the CEseparation efficiency. FITC-labeled components in the cellular membrane of single human erythrocyte cells were detected by using laser induced fluorescence. Aretention time precision of 0. 9% RSD(n=4) for FITC, and an average separation efficiency of 18 μm plate height for FITCwere achieved.
    Manipulation,Transport and Quantal Release Monitoring of Single Cells on a Microfluidic Device
    CHENG Wei, HUANG Wei-Hua, PANG Dai-Wen, WANG Zong-Li, CHENG Jie-Ke, CUI Da-Fu, QU San-Fu, ZHENG Cong-Yi
    2003, 24(9):  1585-1587. 
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    Anovel microfluidic device was developed for on-chip manipulation and monitoring exocytosis of single cells. The microfluidic device consists of a top layer of PDMS containing channels for introducing cells and stimulants and a bottom glass layer into which a cell microchamber was etched. By using hydraulic pressure, single cells were transported and located on the microfluidc chip. After the location of single PC12cells on the microfluidic chip, the cell was stimulated with nicotine that was also introduced through the microchannels, and the quantum release of dopamine from the cell was detected by ampero-metric determination with our designed carbon fiber microelectrode. The results demonstrate the convenience and efficiency of using the microfluidic chip for monitoring of single cells, and offered a new profile for the analysis of single cells on the microfluidic devices.
    Studies on Purification and Bioactivity of 17400 Shark Cartilage Angiogenesis Inhibitor
    ZENG Feng, YANG Wei-Xing, CUI Kun-Yan, LIU Wei, ZHANG Zhan-Xia, YU Jian-Xiu, PANG Yi
    2003, 24(9):  1588-1591. 
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    SCAI-c, another angiogenesis inhibitor from shark cartilage of Guangdong Yangjiang, was purified and the bioactivity of SCAI-c were investigated. The 1. 0 mol/Lguanidine and 0. 02 mol/L MES(at 28 ℃) extracts of shark cartilage was centrifuged at 6000 r/min for 30 min and the pellet was discarded, and the supernatant was recentrifuged at 12000 r/min for 30 min, then ultrafiltrated and fractionally precipitated with 25%-90% acetone. The precipitate was applied to a Sephadex G-75 gel column and eluted after the predominand peak of A280nmabsorbing material with 0. 05 mol/L Tris-HCl buffer (containing 0.02 mol/L NaCl and 0. 02% NaN3). The material Bwere composed of three single peptides with molecular mass of 17600, 15000, 12600, then were purified by using reverse-phase HPLC, the eluate of Cwas collected, dried and observed by chicken chorioallantoic membrane. The pure inhibitor was homogeneous as a single band on a silver-stained 12. 5% sodium dodecyl sulfate-polyacrylamide gel. SCAI-c has a molecular weight of 17600, and could specifically inhibit angiogenesis of the chorioallantoic membrane of chick embryos, and the inhibitory effect of angiogenesis was SCAI-c concentration dependent, but the concentration of SCAI-c increased to 0. 5 μg/μL, chick embryos died about to 20%-30%. Inhibitory characteristic of SCAI-c was similar with that of SCAI-a. They are specific angiogenesis inhibitor, and may be a useful drug on tumor therapy in some day.
    Studies on Synthesis of 2-Substituted-purine Derivatives
    LIU Fu-Sheng, YU Shi-Tao, GE Xiao-Ping, YANG Jin-Zong
    2003, 24(9):  1592-1598. 
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    The Stille coupling reaction between 2-iodo-9-benzylpurine and RSnBu3and the nucleophilic addition and cycloaddition of 2-vinyl-9-benzylpurine were studied. Aseries of new 2-substituted purined-erivatives were synthesized and characterized by elemental analysis, 1HNMR, 13CNMR and MS. It was demonstrated that the reaction mechanism between 2-vinyl-9-benzylpurine and benzenethiol was oxidative addition rather than nucleophilic addition. The structure of the main product was determined by single-crystal X-ray method.
    Synthesis and Herbicidal Activity of New Sulfonylurea Derivatives
    YE Guo-Zhong, FAN Zhi-Jin, LI Zheng-Ming, LI Yong-Hong, GAO Fa-Wang, WANG Su-Hua
    2003, 24(9):  1599-1603. 
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    The sulfonylurea herbicides have been characterized by broad-spectrum of weed control at ultra-low dosage of application, good crop selectivity and low mammalian toxicity. Because of its high herbicidal activity, phototoxicity of sulfonylurea herbicides residues to succeeding crops and weed resistance has become the very important factors affecting its further development in China. In order to search for more environmental-benign sulfonylurea herbicides and study their structure-activity relationship, on the basis of study on a new sulfonylurea herbicide N-[(4'-methyl) pyrimidin-2'-yl]-2-nitro-phenylsulfonyl urea, also called monosulf uron, under commercialization in China, 19 novel sulfonylurea compounds modified at the bridge of urea and 3 related aminopyrimidines were synthesized. The structures of all compounds synthesized were confirmed by elemental analysis and 1H NMR. Preliminary herbicidal activity of the new sulfonylurea compounds derived from sulfonylurea bridge was determined by ALSscreening in vitro and pot bioassay experiment (in vivo). The results indicate that some compounds show good activities against ALS in vitro from Pisum sativum L. and Brassica napus L..
    Synthesis and Characterization of 12-Acyloxyimino-1,15-pentadecanolides
    ZHANG Jian-Jun, DONG Yan-Hong, LIANG Xiao-Mei, WANG Dao-Quan
    2003, 24(9):  1604-1609. 
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    By the addition with acraldehyde, ring-enlargement and Nef reaction, 12-acyloximino-1, 15-pentadecanolides were synthesized from α-nitro-cyclododecanone. cis- and trans-isomers of 12-acyloxyimi-no-l,15-pentadecanolides were obtained by oximation, O-acylation and silica gel column chromatography separation, respectively. The structure of all the title compounds were confirmed by IR, 1HNMR and elementary analysis. Their configurations and conformations were determined by the crystal X-ray analysis of a representative compound and 1HNMR. The results show that the oximation of 12-oxo-l,15-pentade-canolide displays low selectivity for cis- and trans- isomers and the preferred conformation of the ring skeleton is[23434], with the carbonyl group and oximido group present in the two different corner-carbon positions, respectively.
    Synthesis and Chromatographic Properties of a Novel Phenyl Carbamate Perderivatized β-Cyclodextrin Bonded Silica Chiral Stationary Phase
    ZHOU Ai-Ling, WANG Xiu-Ling, HUANG Jun-Min, WANG Xin-Sheng, GAO Ru-Yu
    2003, 24(9):  1610-1614. 
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    Anovel chiral stationary phase has been prepared by immobilized of(mono-6-ethylene diamine-6-deoxy-2, 3, 6-perphenylcarbamated)β-cyclodextrin onto the surface of silica gel via the spacer 3-iso-cyanatopropyl-triethoxysilane with an extended application of the ester exchange reaction, in order to achieve the following two aims: firstly, we tried to use a facile method to get a characteristic multimode chiral stationary by adding more effective interaction sites ; secondly, we wanted to achieve the separation of chiral organophosphorus compounds. The resulting bonded silica stationary phase was characterized by the bonded density of derivative β-CDcalculated from the results of C, Hand Nelemental analyses and spectrum analysis, etc.. The column performance was up to 48000 plates/m, and symmetry factor up to 1. 095. Aseries of fifteen 2-(thiazolyl)-α-amidophosphonates organophosphorus compounds were successfully separated into their enantiomers in the normal phase of HPLCfor the first time. Some of them could be separated in baseline, good enantioseparations with separation factors of a up to 1. 789. Strong π-π interaction or dipole-dipole interaction, hydrophobic interaction etc., contribute to the possible chiral recognition mechanism.
    Highly Enantioselective Transfer Hydrogenation of Aromatic Ketones
    PAN En-De, LI Yan-Yun, DONG Zhen-Rong, CHEN Jian-Shan, LI Bao-Zhu, ZHANG Hui, GAO Jing-Xing
    2003, 24(9):  1615-1617. 
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    Enantioselective reduction of prochiral ketones with 2-propanol or formic acid catalyzed by chiral metal complexes has been developed as a synthetic method complementary to asymmetric hydrogenation in the past decade. However, these processes are necessary to be improved for practical use in organic synthesis because of low catalytic activity and insufficient enantioselectivity. In this paper, we wish to report an excellent catalytic system generated in situ from iridium complex IrCl(Ph3P)3and chiral tetradentate di-aminodiphosphine ligand for asymmetric transfer hydrogenation of various aromatic ketones. For isobuty-rophenone transfer hydrogenation, the corresponding optically active alcohol was obtained in 93% yield and with up to 99% e. e. after 5h at 28℃. Propiophenone was a better substrate with respect to catalytic activity and enantioselectivity in the presence of base as a co-catalyst. The conversion of propiophenone reached 95. 8% and the turnover number as high as 3193h-1. These results will provide a useful index for further designing practical chiral catalytic systems.
    Synthesis of Homoallyl Alcohol by Allyl samarium Bromide and Carbonyl Compounds
    YU Ming-Xin, ZHANG Yong-Min
    2003, 24(9):  1618-1620. 
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    Samarium reacts with allyl bromide to form allylsamarium bromide at room temperature in THF. And allylsamarium bromide reacts with carbonyl compounds to give homoallyl alcohols. The yields of products for aromatic aldehydes are higher than those of the products for aliphatic aldehydes. The effect of the group on aromatic ring is not obvious. Two molar allylsamarium bromide reacts with a molar ester to produce the corresponding homoallyl alcohol. The structures of products were characterized by IR, 1HNMR and MSspectra.
    AFM Studies on DNA Covalently Immobilized on Mica Modified by APTES-GA
    JI Mei-Ju, HOU Peng, SHEN Jia-Yao, LI Song, LU Zu-Hong, HE Nong-Yue
    2003, 24(9):  1621-1623. 
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    The immobilization of DNA on self-assembled layers of 3-aminopropyltrimethoxysilane (APTES) and glutaraldehyde(GA) on mica wafers by chemical coupling has been studied by using atomic force microscopy (AFM). The DNAused for our investigation is amplified by PCR and primers were labeled by -NH2at their 5' terminal. The surfaces were analyzed with X-ray photoelectron spectroscopy (XPS) and AFM. The results from XPS and AFM show that APTES-GA modified mica can be formed and the flatness of mica is adapted to AFM images. We found that DNA can be readily immobilized on mica. The covalent coupling between the aldehyde-terminated membrane and the both H2N-groups in double strands DNA results in the immobilization of the DNA straightly.
    Quantum Chemistry Studies on Tetrahydroimidazobenzodiazepinone Inhibitors of HIV-1
    XU Xuan, LUO Yi-Fan, XU Zhi-Guang, ZHAO Jun, LIU Zhan-Mei
    2003, 24(9):  1624-1628. 
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    The optimization of geometries and electronic structures of 20 TIBO (Tetrahy-droimidazobenzodiazepinone) HIV-1 inhibitors had been performed by MNDO and ab initio quantum chemical methods. Asignificant QSARwas obtained as below:Pc= -10. 425+4. 216×10-2V-19. 935QN12-4. 211Q3x. The BP artificial neural network method can be used to predict the activities more accurately. The results show that (1) the activities of TIBO derivations will increase due to the larger volume and less polarity of molecules; (2) the hydrogen atom connected to nitrogen atom in ring Cmay be the active atom taking positive charge; (3) the R' atom(Sor O) is the electron donor to acceptor. The frontier molecular orbital component of Sis much bigger than that of O, and Sis more puweiful election donor than O, which indicate why the sulfur has a better activity than oxygen; (4) the electron acceptor substituents in ring Acan enhance the activity of TIBOderivations. Since smaller distance between positive and negative charge center leads to small polarity, 3-substituted derivations show better activities than 2-substituted derivations.
    Kinetics Study of Phenol Hydroxylation by Hydrogen Peroxide over Copper Hydroxyphosphate Catalyst
    DING Hong, DI Yan, WANG Run-Wei, MENG Xiang-Ju, JIANG Da-Zhen, XIAO Feng-Shou
    2003, 24(9):  1629-1632. 
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    The kinetics of phenol hydroxylation over copper hydroxyphosphate in the presence of hydrogen peroxide as an oxidant was studied systematically. The influences of the amount of catalyst, the concentration of hydrogen peroxide and phenol, as well as the temperature were investigated. The reaction orders of the reactants and catalyst were obtained by using initial reaction rates method being first order with respect to the amount of catalyst and the concentrations of phenol and hydrogen peroxide. Also, the apparent activation energy was calculated to be 12 kJ/mol.
    New Method for Preparing Zeolites Matrix Nanometer Noncrystal Soft Magnetic Materials and Their Magnetism
    Hasiqimuge, LI Song-Bo, XU Ai-Ju, Guoxingbatu
    2003, 24(9):  1633-1636. 
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    By using stepwise hydrothermal synthesis methods, magnetic materials Fe3O4and SmCo5were successfully assembled into the channels of zeolites ZSM-5, Naβ and NaY, whose apertures were 0. 56, 0. 73 and 0. 78 nm, respectively. Furthermore, their magnetic hysteresis loops and magnetism parameter, Ms, Mrand Hcwere determined satisfactorily. After being assembled, the coercivity Hcof block crystal Fe3O4was reduced from 8117 to 1114 A/m, while the coercivity Hc of block crystal SmCo5was reduced from 55863 to 5491 A/m. That shows the nanometer noncrystal soft magnetic materials are formed. It was caused by the quantum size effect of the nanometer particle. It was proved that the magnetic materials Fe3O4and SmCo5were assembled into the channels of the zeolites by XRD, IRand magnetic hys teresis loops.
    Characteristic of Phenol Degradation Under Various Electrocatalysis Processes
    ZHOU Ming-Hua, WU Zu-Cheng, WANG Da-Hui
    2003, 24(9):  1637-1641. 
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    Phenol degradation with three electrocatalysis processes; anodic electrocatalysis(AE), anodic-cathodic electrocatalysis (ACE) and ferrous ion catalyzed anodic-cathodic electrocatlysis (FeACE) were compared. At current of 0. 25 A, the removal rate of CODin wastewater is only 30% by using AE, while it is 60% by using ACE, and 90% by using FeACE. The main intermediates during the phenol degradation are hydroquinone, catechol, resorcinol, benzoquinone, maleic acid, fumaric acid and oxalic acid. When FeACE was used, formic acid was also observed and the final product is carbon dioxide. FeACE can increase the removal rate of COD, and benefit the rapid elimination of toxic intermediates as well. Furthermore, the process could reach the mineralization of organic compound, showing much more optimistic potential for the environmental protection. The mechanism of organic degradation was confirmed to be the role of hydroxyl radical by using salicylic acid as the radical trapping, which are more likely to attack benzene ring in the sequence of p-, m-, o-. Adegradation mechanism for phenol was also proposed.
    Studies on Photo-induced Amphilicity of TiO2Thin Film and Printing Properties with Water-soluble Ink
    SUN Wen-Tao, ZHOU Shu-Yun, JIANG Lei, CHEN Ping
    2003, 24(9):  1642-1644. 
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    The photo-induced super-amphilicity of TiO2thin film has won a great interest in some fields. The relationship between the wettability of TiO2thin film and the illumination time, as well as light intensity, was investigated in this paper. The effect of the illumination time on the adsorption amount of a water soluble dye was examined. The experiment results of transferring the dye from TiO2film to paper primarily show that TiO2thin film could serve as a new type printing material.
    Theoretical Studies on the Conductivity and Bonding of Boron-nitride Nanotube
    ZHANG Gui-Ling, DAI Bai-Qing
    2003, 24(9):  1645-1647. 
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    Electronic structures of boron-nitride nanotubes of zigzag(N,0) and armchair(N,N) types for the annotube diameter N=4, 5 and 6 were calculated by B3LYP method. The bonding character and the conductivity of these nanotubes were discussed from the calculated results of energy bands, density of states (DOS) and bond orders, and were compared with those of carbon nanotubes.
    Quantum Chemical Investigation on the Reaction Mechanism of OBrO with NO
    ZHAO Min, PAN Xiu-Mei, LIU Peng-Jun, SUN Hao, SU Zhong-Min, WANG Rong-Shun
    2003, 24(9):  1648-1651. 
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    The reaction mechanism between OBrO and NO was studied by using the B3LYP/6-311+G**and the high-level electron-correlation CCSD(T)/6-311+G**single-point levels. The geometries of reac-tants, transition states, intermediates and products were optimized and verified by frequency analysis. The results show that the reaction is multi-channel and multi-step exothermic. It may proceed on singlet and triplet potential energy surface(PES). OBrO and NO may react via addition or addition-elimination mechanism to form the products BrONO2and BrO+NO2.In view of energy, the channel of forming the products BrO+NO2is more favorable.
    Studies on the Kinetics of Unseeded Nucleation of Aluminum Trihydroxide from Supersaturated Sodium Aluminate Solutions
    LI Jie, CHEN Qi-Yuan, YIN Zhou-Lan
    2003, 24(9):  1652-1656. 
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    Under isothermal batch crystallization condition, unseeded nucleation of Al(OH)3crystals from supersaturated caustic aluminate solution was studied by in situ conductivity and absorbance measurements. The nucleation kinetics of Al(OH)3crystals were obtained and the influence of H2O and Na+on the unseeded nucleation were investigated. The experimental results indicate that, when the molar ratio of Na2O to Al2O3is fixed in Na2O-Al2O3-H2O system. The crystallization of Gibbsite display two kinds of nucleation mechanism with variation of H2O content. When Na2O in the crystallization system is substituted by K2O, the induction period of the crystallization is prolonged, but the active energy and the reaction order are all found to be independent of the alkali ion. It can be concluded that, the nucleation of Al(OH)3crystals in supersaturated alminate solution is a chemical reaction controlled process, H2O and Na+take part in the reconstruction of alminate ions though they are not present in the overall-reaction of Al(OH)3crystallization. H2Ois related to the key procedure of the decomposition of supersaturated sodium alminate solution. Yet, Na+has little effects on the controlling-step.
    Studies on Chiral Molecular Recognition of Salen Zn with Amino Acid Esters
    RUAN Wen-Juan, ZHANG Yu-Ling, ZHAO Xiao-Jing, JIANG Dong-Qing, ZHU Zhi-Ang
    2003, 24(9):  1657-1661. 
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    Using UV-Vis spectrophotometer technique, the association constants of chiral molecular recognition reaction were measured between Salen Zn and series D- and L-amino acid esters in CHCl3. The association constants decrease in the orders of K(LeuOMe) >K(ValOMe)>K(AlaOMe); K(ThrOMe)>K (SerOMe)>K(TyrOMe) and K(D)>K(L). The thermodynamic parameters were determined by Van't Hoff equation. The phenomenon of enthalpy-entropy compensation and enan-tiomer selection were discussed. In addition, the theory studies by means of molecular mechanics and quantum chemistry computation were performed, which gave the reasonable explanation for the experimental results and the behavior of molecular recognition.
    Photo-induced Enhancement of Dispersion of Nano-TiO2in Water Media
    WANG Bao-Hui, CHEN Ying, SONG Hua
    2003, 24(9):  1662-1665. 
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    By the measurements of wettability, ξ potential, viscosity and sedimentation, the technique of surface chemistry was used to characterize the dispersion behavior under with and without UVirradiation condition. Photo-induced enhancement was found for the dispersion of nano-TiO2in water. The photoac-tion highly improves the dispersion and stability. The effect is attributed to photogeneration of hydrophilic TiO2surface through an investigation of the mechanism.
    Correlation Between Microstructure and Electrochemical Performances for Coal-tar Pitch Based Meso-carbon Microbeads
    ZHENG Hong-He, ZHANG Hu-Cheng, WANG Jian-Ji, SU Yu-Chang, XU Zhong-Yu
    2003, 24(9):  1666-1670. 
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    Coal-tar pitch based meso-carbon microbeads(MCMB) were heat-treated with a certain technology under different maximum heat-treatment temperatures(HTTmax). Microstructure parameters of the heat-treated samples were characterized by XRD and Raman spectroscopic studies. Electrochemical performances of the samples used as the negative electrodes in lithium ion secondary batteries were examined through galvanostatic and cyclic voltametry measurements. Correlation between microstructures and electrochemical performances for MCMB was discussed. The results reveal that with increasing HTTmax, mi-crostructure characteristics of the MCMB undergo a structural transition from pyrolytic carbon to artificial graphitic carbon. Accordingly, the lithium ion storage mechanism of the electrode exhibits a transition from pin-pore storage to lithium insertion between carbon layers. The crystalline size along a axis (La) of MCMB does not greatly increase when being heat-treated due to the peculiar arc arrangement of carbon layers in MCMB. The appropriate Lavalue of the MCMB obtained under extremely high temperatures is the internal reason for its excellent electrochemical performances.
    Structure Influence of Fe3+Doped TiO2/SiO2Film on the Photocatalytic Properties
    FU Hong-Gang, WANG Jian-Qiang, REN Zhi-Yu, YAN Peng-Fei, YU Hai-Tao, XIN Bai-Fu, YUAN Fu-Long
    2003, 24(9):  1671-1676. 
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    Fe3+ion doped titanium dioxide films coated on silica(Fe3+-TiO2/SiO2) were prepared by sol-gel method. The obtained films were more effective than TiO2nano-size powder in decomposing Rhodamine Bunder irridation with Xe lamp. In the Fe3+doping system, the optimum value of the Fe3+/Ti4+(atomic ratio ) was 0. 03 % for the photocatalytic degradation of Rhodamin B. The experimental results suggested that the photocatalytic reactions with the titanium dioxide nanosize powder and film as the catalyst proceed in two different degradation mechnisms. By the characterization using XRD, SEM, Raman, and FTIR technologies, we can conclude that the surface layer structure of TiO2film on silica and the formation of Ti-O-Si bond play important roles with the increasing of degradation efficiency, and result in two different decomposition mechanisms for film and power.
    A New Pb-Sm-Sn Positive Grid Alloy
    ZHOU Yan-Bao, YANG Chun-Xiao, MA Min, ZHOU Wei-Fang, LIU Hou-Tian
    2003, 24(9):  1677-1679. 
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    The anodic behavio of Pb-(0. 075%-0. 73%)Sm-0. 63%Sn and Pb-0. 088%Ca-0. 63%Sn alloys in sulfuric acid solution has been studied by using cyclic voltammetry, linear sweep voltammetry and impedance-time curves. The experimental results show that samarium in the Pb-Sm-Sn alloy can inhibit the growth of the anodic corrosion layer(PbO2) formed on the alloy. Moreover, the evolution of oxygen at the Pb-Sm-Sn alloy electrode is less than that at the Pb-Ca-Sn alloy electrode. 2V-200 A·h VRLA batteries were manufactured by using the above two alloy positive grids separately. he corrosion layers formed on the positive gird surfaces after the life test of the batteries were observed by SEM. The results of the test show that the capacity loss of the battery with the Pb-Sm-Sn positive grids is significantly less than that of the battery with the Pb-Ca-Sn positive grids, and the longer floating charge life of the battery with the Pb-Sm-Sn positive grids is caused by the better corrosion-resistant performance of the Pb-Sm-Sn alloy with the anodic corrosion layer having a finer grain structure.
    Investigation on Electrochemical Properties of La1-xMgx(NiCoAl)3.6Alloy Employed as Negative Electrode in High Power MH-Ni Battery
    ZHANG Xin-Bo, ZHAO Min-Shou
    2003, 24(9):  1680-1682. 
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    The La1-xMgx(NiCoAl)3.5system compounds, La0.9Mg0.1Ni3.1Co0.3Al0.2, La0.7Mg0.3Ni3.1· Co0.3Al0.2, La0.8Mg0.2Ni3.0Co0.4Al0.2and La0.9Mg0.1Ni3.1Co0.2Al0.3have been prepared by arc melting of constituent elements in Ar atmosphere. The electrochemical properties of these alloys have been studied through the charge-discharge recycle testing. The X-ray diffraction(XRD) analysis reveals that the as-prepared alloys have quite different crystal structures from that of AB5-type alloy. It can be found that La1-xMgx(NiCoAl)3.6system alloys are capable of performing a high rate discharge. The as-prepared alloys have much higher middle voltage than those of AB5-type alloy during the discharge period.
    Resonance Enhancement of Electro-optical Effect by Second-order Nonlinear Optical Polyurethane
    LI Xu-Hua, YUAN Qiao-Long, WANG De-Ning, CAO Zhuang-Qi, SHEN Qi-Shun
    2003, 24(9):  1683-1685. 
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    Anovel cross-linked polyurethane with high second-order nonlinear optical(NLO) activity and high thermal stability was synthesized from disperse Red-19 and the trimer of 2,4-toluene diisocyanate. The electro-optical coefficient(r33) of the polyurethane and the electro-optical modulation efficiency of the spatial modulator were measured at lasers of 632, 650, 832 and 980 nm by the improved attenuated-total-reflection technology after the polyurethane was poled and cured. The results indicate that r33and the modulation efficiency increase in the absorption region of the polyurethane with the descending of the incident laser wavelength. Further theoretical and experimental researches show that the enhancement of the electro-optical effect is resulted from the complex refractive index change. The change increased with the ab-sorbance of the polyurethane due to the resonance of the NLO polyurethane and the incident laser. As a result, for spatial electro-optical(EO) modulator like attenuated-total-reflection EOmodulator, the absorption region can be effectively utilized notonly because the effective optical path length is much shorter that of a waveguide EO modulator and optical losses do not present a serious problem but also because the electro-optical effect will be strengthened by the resonance.
    Preface
    Synthesis and Characterization of Dumbbell-like C70Polystyrene Derivatives
    SHEN Jian-Zhong, GUO Chong-Dong, CHEN Yu, CAI Rui-Fang
    2003, 24(9):  1686-1690. 
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    The dumbbell-like C70polystyrene derivatives were prepared through direct reaction of the "living" dianionic polystyrene obtained by sodium naphthalene-initiated anionic polymerization with C70in the C6H6/THF mixed solvents. The products were characterized by UV-Vis, FTIR, GPC, 1H NMR, 13CNMR, SEM, XRD, TGA and DSC techniques. The GPC analysis showed the C70-styrene copolymers and the parent polystyrene have nearly the same molecular weights. From the GPC data and the C70contents of the copolymers determined by TGA, it was confirmed that the C70-polystyrene derivatives are linear dumbbell-like macromolecules in which two C70molecules end-capped together by a polystyrene chain.
    Articles
    Studies on the Relationships Between the Connected Ways and the Properties of Poly (ether ether ketone) Copolymers
    LI Hui, ZHOU Hong-Wei, CHEN Chun-Hai, WU Zhong-Wen
    2003, 24(9):  1691-1694. 
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    Anovel alternate copolymer of poly (ether ether ketone), 50% PEDEK-PETMDEK was designed and synthesized successfully by aromatic nucleophilic substitution polycondensation. The structure of the alternate copolymer was determined by 1HNMR. The properties of the 50% alternate copolymer, 50% random copolymer, homopolymer PEDEK and PETMDEK were studied by DSC and WAXD etc.. We found that solubilities and thermal properties of 50% alternate copolymer and 50% random copolymer were quite different, the former is amorphous, and could be easily dissolved in common organic solvents,while the latter is a semi-crystalline polymer and could not be dissolved in almost any solvents except con-centrated H2SO4just like the homopolymer PEDEK. The properties of 50% alternate copolymer are more like those of the homopolymer PETMDEK. The glass transition temperature of the 50% alternate copolymer is higher than that of the 50% random copolymer.
    Effects of Added Salts on Intra-and Inter-molecular Fluorescence NRET of Sulfonate Polyelectrolytes
    SUN Qi-Long, WANG Chao-Yang, REN Bi-Ye, LIU Xin-Xing, ZENG Fang, LIU Ping, TONG Zhen
    2003, 24(9):  1695-1699. 
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    Naphthalene and pyrene singly and doubly labeled polyelectrolytes were prepared by radical copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) from 5% to 99% (molar fraction) and N, N-dimethylacrylamide with the label monomers. Fluorescence nonradiative energy transfer (NRET) was measured in NaCl and CaCl2aqueous solutions up to the concentration of 6×10-3mol/L. Intra- and inter-molecular NRET determined with doubly labeled samples and mixtures of singly labeled samples indicated that owing to the salt screening effect, increasing salt concentration enhanced the NRET and the enhancement of calcium cation was stronger than that of sodium cation. The normalized NRET En, defined as the NRET in salt solution relative to that in water for a given sample, showed that intramolecular Endecreased with the increase of charge density FAMPSin the samples with a maximum at FAMPS≈0. 45. In contrast, the intermodular Enincreased with the increase of FAMPS, suggesting that there were inhomogeneous intermolecular aggregates in polyelectrolyte solutions due to the condensed coun-terions even at a concentrations lower than the overlap threshold c*.
    A New and Easy Post Functionalization Approach to Synthesize Polymers Containing Indole-based Chromophore Side Groups
    LI Zhen, QIN Jin-Gui, LI Shao-Jun, YE Cheng
    2003, 24(9):  1700-1703. 
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    A new synthetic strategy was developed to prepare polymers with indole-based chromophore side chains. Thus, polymers 1 that contain indole groups as side chains was obtained by a direct reaction. And then a post azo coupling of p-nitrobenzenediazonium fluoroborate toward the indole ring in polymers 1 afforded indole-based chromophore-functionalized polymers 2. The polymers were well characterized and exhibited an excellent solubility in common organic solvents. The poled film of polymers 2 reveals a resonant d33value of 25 pm/V obtained by second harmonic generation (SHG) measurements.
    Studies on Carbosilane Liquid Crystalline Dendrimer of the Second Generation--Containing 36 4-Hexyloxyazobenzene Groups in Its Periphery
    ZHANG Qi-Zhen, LIU Jian-Qiang, YIN Xiao-Ying, ZHANG Jing-Zhi, ZHAO Xiao-Guang, LI Guang, JI Yi-Ping
    2003, 24(9):  1704-1707. 
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    The divergent synthesis of a new carbosilane liquid crystalline(LC) dendrimer of the second generation(D2) was described. Thirty-six 4-hexyloxyazobenzene groups (M3) were used as mesogenic fragments and attached to its periphery. The structure and properties of D2 were characterized by elementary analysis, 1HNMR, MALDI-TOF-MS, IR, UV, polarizing optical micrograph, DSC and WAXD. It is argued that mesophase of nematic type is realized. It is shown that the mesophase type of the dendrimer D2 and D1 essentially depends on the chemical nature of the mesogenic groups and is the same as that of mesogenic unites. The phase behavior of D2 in LC state is K90N105H113N75K. The melting point of D2 decreases 26-33℃ than that of M3, the temperature at its clear point decreases 3-15℃ than that of M3 and its mesophase region is enlarged 11-30 ℃ than that of M3. The melting point of D2 decreases 2-3℃ than that of D1, the temperature at its clear point decreases 11-21℃ than that of D1 and its mesophase region decreases 8-19℃ than that of D1.
    Synthesis and Properties of Polyaniline Attached to Cu-Phthalocyanine Functional Group in Side Chain
    SUN Jian-Ping, WU Hong-Cai, LI Bao-Ming, FENG WEI, WEI Wei
    2003, 24(9):  1708-1711. 
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    Using Cu-phthalocyanine, chlorosulfonic acid and sulfone chloride as raw materials, Cu-phthalocyanine sulfonic acid chloride was synthesized. The polyaniline containing Cu-phthalocyanine functional group in side chain (PAnCuPc) was synthesized by using Cu-phthalocyanine sulfonic acid chloride and intrinsic polyaniline. The designed chemical structure of PAnCuPc and its intermediate product can be proved by means of the elementary analysis, IR and UV-Vis. PAnCuPc is soluble in aprotic solvents such as NMP, DMF, DMAc and DMSO. It is even soluble in common solvents with a low boiling point such as THFand chloroform. In comparison with the intrinsic polyaniline, the absorption peaks of PAnCuPc shift to a low frequency direction in IRspectrum. The absorption of PAnCuPc is very intense in the range of visible light and near-infrared through UV-Vis spectrum. It can be seen from transition electron microscopy and X-ray diffraction that the crystallinity of PAnCuPc is obviously improved.
    Morphology and Phase Behavior of the PET/HBA/HQ/TA Copolyesters
    LAN Qiang, CHENG Dan, YU Ying, BU Hai-Shan
    2003, 24(9):  1712-1716. 
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    Aseries of etching methods were developed for the morphology observation of liquid crystalline copolyester. Phase behavior of the PET/HBA/HQ/TA copolyester was investigated by SEM after etching. Atwo-phase structure of these copolyesters was found. When PETmolar fraction is lower than50%, HBA/HQ/TA-rich-phase is a continuous phase, while the dispersion particles are PET-rich-phase. When PET molar fraction is equal to or greater than 50%, PET-rich-phase constitutes continuous phase, while HBA/HQ/TA-rich-phase forms dispersion particles which are composed of fibers. Therefore this PET/HBA/HQ/TA copolyester is not a random copolymer but a block one with long PET blocks.
    Preparation and Structure of Fe3O4Nanoparticle-polystyrene Uniformly Dispersed System
    ZHANG Yong-Hua, CHEN Shou-Ming, CHEN Jian-Hua, XIONG Hong-Bing, ZHANG Qi-Wei, SHEN Hui, GONG Ke-Cheng
    2003, 24(9):  1717-1720. 
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    The nano-particles of Fe3O4were prepared by a chemical co-precipitation method. Astable polymerizable magnetic fluid of nano-Fe3O4was obtained by dispersing oleic acid-coated Fe3O4nano-particles in styrene as a carrier liquid. Auniformly dispersed system of nano-particles of Fe3O4in polystyrene has been acquired by the free radical polymerization of polymerizable magnetic fluid. The crystallization behavior and the surface of Fe3O4nano-particles before and after the modification by oleic acid were investigated by WXRD and FTIR, respectively. The particle size and size dispersion of Fe3O4nano-particles in styrene and polystyrene were studied by TEM. The glass transition temperature (Tg) and the thermal stability of nano-Fe3O4/polystyrene dispersion system were also studied by means of DSC and TGA, respectively. The results indicate that the nano-Fe3O4is a cubic crystal, the particle size is 10 nm on an average, the oleic acid molecules are chemically adsorbed on the surface of Fe3O4nano-particles, the modified Fe3O4nano-particles are dispersed homogeneously in styrene and in polystyrene. The temperature at sharp weight loss of polystyrene containing only 1.8% Fe3O4nano-particles is 13 Khigher than polystyrene and its saturation magnetization is 17. 43 emu/g.
    A Novel Preparation of Highly Interconnected Macroporous Poly(ethylene glycol) terephthalate-b-poly(butylene terephthalate) Copolymer Scaffolds
    ZHANG Ai-Ying, FENG Zeng-Guo, ZHANG Yong, WANG Lian-Cai, QIU Rong-Xin
    2003, 24(9):  1721-1723. 
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    Based on poly(ethylene glycol) terephthalate-b-poly(butylene terephthalate) multiblock copoly-mers, highly interconnected macroporous scaffolds are fabricated via hydrolysis in PBS. The scaffold morphologies are closely related to polymer composition and aging time. The copolymers with molar ratios of PEGT to PBT 31 : 69 and 22 : 78 have exhibited highly interconnected macroporous structures after more than 100d degradation. Pore diameters could be controlled within the range of 2-50μm by varying the aging time, and the porosity of scaffold treated for 100 d is about 88% for the copolymer with PEGT molar fraction of 31%. However, those copolymers with PEGT molar fraction of 17% and 44% could not form porous matrices. Therefore, the content of hard domains as physical cross-linking junctions in the matrix is of critical importance for the preparation of scaffold.
    Studies on Vibrational Circular Dichroism Spectroscopy of Chiral Cavity in Rigid Cyclic Oligomers Containing 1,1'-Bi-2-naphthyl Moiety
    CAO Hui, BEN Teng, LIU Xin-Cai, ZHAO Xiao-Gang, LIU Na, WANG Xing, ZHANG Wan-Jin, WEI Yen
    2003, 24(9):  1724-1726. 
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    The chiral behavior of chiral cavity in rigid cyclic oligomers containing1,1'-bi-2-naphthyl was investigated by vibrational absorption and circular dichroism(VCD) spectroscopy, respectively. The VCD spectra of chiral rigid oligomer were analyzed by comparison with IRspectra. Much useful information was obtained at the end from the discussion.
    Molecular Structure of Poly (vinyl chloride) Resin Prepared by a New Heterogeneous Polymerization Process
    BAO Yong-Zhong, WENG Zhi-Xue, HUANG Zhi-Ming
    2003, 24(9):  1727-1729. 
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    Vinyl chloride(VC) heterogeneous polymerizations, using n-butane as the reaction medium and bis(4-tert-butylcyclohexyl) peroxydicarbonate as the initiator, were carried out to prepare poly (vinyl chloride) (PVC) resins. The chain structure, molecular weight (Mw) and molecular weight distribution (MWD) of resulting PVCresins were characterized by using 1HNMR and GPC, respectively. It was shown that more PVCchains with -CH2-CH2Cl end group were formed in the new polymerization process. The Mw of resulting PVC was lower than that of suspension PVC prepared at the same polymerization temperature and the index of MWD was greater. The Mw decreased and index of MWD increased with the increase of polymerization conversion. The variations on PVCchain structure, Mw and MWD were caused by the chain transfer reaction of PVC macroradicals to n-butane.
    Synthesis and Characterization of Functional Polycarbonates
    LIU Zhi-Lan, ZHANG Jian-Min, ZHUO Ren-Xi
    2003, 24(9):  1730-1732. 
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    New polycarbonates were synthesized by ring-opening polymerization from the protected cyclic carbonate 9-phenyl-2,4,8,10-tetraoxaspiro-[5,5]undecan-3-one in bulk at 190 'Cunder the catalysis of various catalysts, such as aluminum isobutoxide [Al(O'Bu)3], aluminum isopropoxide [Al(O'Pr)3] or stannous octanoate [Sn(Oct)2]. The effects of different catalysts, reaction time, and monomer-to-catalyst molar ratio on the molecular weight and yield were investigated. The polycarbonates obtained were characterized by FTIR, 1HNMR, GPC and DSC. The protecting benzal group was removed by hydrolysis with 80% acetic acid to give a functional polycarbonate containing 45% hydroxyl group.
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