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    30 January 2019, Volume 53 Issue 1 Previous Issue    Next Issue
    Research Report
    Preparation and Self-polymerization Kinetics of N-methyl-N, N-divinyl-3-dehydroabietoyloxypropan-1-ammonium Bromide
    Haibo ZHANG,Jianxin JIANG,Shibin SHANG,Zhanqian SONG
    2019, 53 (1):  1-7.  doi: 10.3969/j.issn.1673-5854.2019.01.001
    Abstract ( 431 )   HTML ( 1433 )   PDF (1352KB) ( 558 )   Save

    Water-soluble rosin monomer N-methyl-N, N-divinyl-3-dehydroabietoyloxypropan-1-ammonium bromide(DMDHAE) was prepared from dehydroabietic acid, 3-bromopropanol and methyldiallylamine, and its structure was characterized by nuclear magnetic resonance(NMR), gas chromatography(GC), elemental analysis, FT-IR, mass spectrometry(MS) and melting point instrument. The results indicated that the purity of monomer was 91%, melting point was 127-131 ℃, and solubility was 1.50-1.60 g/mL; characteristic group peaks were appeared in the NMR and FT-IR spectra, and the mass spectrometry and elemental analysis results were consistent with the theoretical value. The self-polymerization parameter was measured by differential scanning calorimeter(DSC), and self-polymerization kinetics was analyzed with autocatalytic model. The results showed that DMDHAE was polymerizability, the activation energy(Ea) was 124.336 kJ/mol, and mechanism function f(α) was SB(m, n) model.

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    Pd-β/MCM-41 Composite Molecular Sieve in Hydrocracking Waste Cooking Oil Reaction
    Qian ZHAO,Yuanzhen WEN,Haibo JIN,Guangxiang HE
    2019, 53 (1):  8-16.  doi: 10.3969/j.issn.1673-5854.2019.01.002
    Abstract ( 444 )   HTML ( 252 )   PDF (1211KB) ( 448 )   Save

    β/MCM-41 meso-microporous composite molecular sieves were synthesized with β zeolite as silica-alumina source and CTAB as template. And then Pd-β/MCM-41 catalyst was prepared. The catalyst was characterized by XRD, N2 adsorption-desorption, NH3-TPD and XRF. And the catalytic hydrocracking activity of Pd-β/MCM-41 was separately investigated and compared with that of Pd catalysts which were prepared with γ-Al2O3, USY and ZSM-5 as carriers. The study showed that β/MCM-41 composite molecular sieves had both the structures of β zeolite and MCM-41 molecular sieve. Pd-β/MCM-41 catalyst had suitable medium-strong acidity center and suitable pore distribution structure and it had the highest activity of the hydrocracking. Meanwhile, the influence of the catalyst synthesis conditions on the catalyst activity was discussed. The results showed that the best hydrocracking activity on the vegetable oil was acquired as preparation 2% Pd on β/MCM-41 composite molecular sieves by ion exchange and the calcination temperature of 500 ℃. The conversion rate of raw oil reached 85.9%, and the yield of biogasoline could reach 16.4%, and the yield of biodiesel reached 17.8%. The composite molecular sieve catalyst had better thermal stability, regeneration property and prospect for industrial application.

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    Structural Characterization of Rosin-based Magnetic Microspheres and Their Adsorption Properties of Cr(Ⅵ)
    Kechun LI,Jianfang LU,Fuhou LEI,Juying ZHOU,Haitang XU,Yanzhi ZHAO
    2019, 53 (1):  17-24.  doi: 10.3969/j.issn.1673-5854.2019.01.003
    Abstract ( 565 )   HTML ( 116 )   PDF (3364KB) ( 540 )   Save

    The rosin-based magnetic microspheres were synthesized by using maleic rosin acid-ethanediol-acrylic ester and methacrylic acid as functional monomer and ferriferrous oxide as magnetic source via suspension polymerization and amidation reaction. The structural and morphological properties of rosin-based magnetic microspheres were characterized by TG, FT-IR, BET, SEM and magnetic balance, and its static adsorption behavior for Cr(Ⅵ) was analyzed. The results showed that the rosin-based magnetic microspheres had paramagnetism(magnetic susceptibility was 9.123×10-4 cm3/g) and functional group(amino). The specific surface area, pore volume and average pore size were 29.73 m2/g, 0.396 cm3/g and 18.023 nm. And there were many holes in the surface and internal. The optimum static adsorption conditions were obtained as follows: pH value 2, absorbent dosage 0.8 g, adsorbent particle size 72-108 μm. Under these conditions, the equilibrium adsorption(Qe) was 67.5 mg/g after 4 h at 25 ℃ in 50 mL 0.5 g/L Cr(Ⅵ) solution. The pseudo-first-order kinetic equation that could well describe adsorption process was established, and the adsorption processes were affected by film diffusion and intra-particle diffusion. After using for 5 times, the removal rate of microspheres still reached 85% of the first adsorption, which indicated that the microspheres had good reusability.

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    Response Surface Optimization of Hydroxypropyl Chitosan Synthesis
    Rui GUO,Yao ZHANG,Shuang HAN,Ning WANG
    2019, 53 (1):  25-32.  doi: 10.3969/j.issn.1673-5854.2019.01.004
    Abstract ( 538 )   HTML ( 1550 )   PDF (3033KB) ( 464 )   Save

    Hydroxypropyl chitosan(HPCS) was synthesized from chitosan(CTS) and propylene oxide. The structure and morphology of HPCS were characterized by infrared spectroscopy(FT-IR), 1H nuclear magnetic resonance(1H NMR), X-ray diffraction(XRD) and environmental scanning electron microscopy(ESEM). And the effects of the synthesis process on the intrinsic viscosity were investigated. The results showed that the hydroxypropyl group was successfully grafted onto chitosan and HPCS was obtained. On the basis of single factor experiment, the response surface methodology was used to optimize the process. The optimum conditions for HPCS synthesis were reaction temperature 60 ℃, reaction time 6 h, NaOH mass fraction 30%, alkalization time 20 min and the amount of propylene oxide 12.6 g. Under these conditions, the intrinsic viscosity of HPCS was 206.32 mL/g, the relative molecular mass was 2.738×105, and the degree of substitution(DS)was 0.426.

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    Structure and Performance Changes of P34HB/Wood Flour Bio-composite During Natural Degradation
    Shengnan AN,Xiaojun MA,Lizhi ZHU,Lili YU
    2019, 53 (1):  33-39.  doi: 10.3969/j.issn.1673-5854.2019.01.005
    Abstract ( 642 )   HTML ( 287 )   PDF (7623KB) ( 284 )   Save

    Using Chinese white poplar flours(WF) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate)(P34HB) as raw materials, the P34HB/wood flour bio-composite was prepared by hot pressing method. The changes of structure, mechanical property and thermal stability of the composite during natural degradation were studied by scanning electron microscopy(SEM), differential scanning calorimetry(DSC), thermal gravimetric(TG) analysis and mechanical property analysis. The results showed that the earlier stage of degradation was mainly the degradation of P34HB matrix, and the degradation of wood fiber was followed; the P34HB matrix presented honeycomb structures after degradation. The mass loss of the composite showed a near-linear upward trend with the time increasing, and the ratio of mass loss of the composite reached 34.43% after 100 days degradation. TG and DSC results further showed that the main degradation material of the composite was P34HB matrix, and the degradation of wood flour fiber was accompanied in the later stage. The flexural strength and Young's modulus of the composite decreased with the degradation time increasing, and the decrease trends were rapidly in first 10 days, which were from 24.67 and 2 768.25 MPa to 16.72 and 1 339.34 MPa, respectively, and the decrease rates were 32.23% and 51.62%, respectively. After 80 days of degradation, the flexural strength and Young's modulus of the composites reached 6.74 and 469.43 MPa, which decreased by 72.68% and 83.04%, respectively, and then they tended to balance.

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    Effects of Additives in H3PO4 Solution on Properties of Activated Carbon from Walnut Shell
    Yani PAN,Xiaoyun TIAN,Yinsheng DONG
    2019, 53 (1):  40-46.  doi: 10.3969/j.issn.1673-5854.2019.01.006
    Abstract ( 487 )   HTML ( 284 )   PDF (1022KB) ( 540 )   Save

    Activated carbons were prepared from walnut shell by H3PO4 activation and the effects of adding different kinds and contents of additives to H3PO4 solution on the properties of activated carbons were investigated. The adsorption property was characterized by methylene blue and iodine adsorption values. The pore structure parameters, mechanical strength and graphite microcrystalline of activated carbon were tested. When the activated carbons were prepared by walnut shell immersed in H3PO4 solution with the addition of citric acid, sodium citrate, boric acid and saccharin, respectively, the methylene blue adsorption values increased, and the iodine adsorption values and the mechanical strength decreased. This meant the additives promoted the expansion of micropores of activated carbons to mesopores. Adding 0.5% sodium citrate in H3PO4 solution, the activated carbon with the maximum methylene blue and iodine adsorption values was gained, which were 236.5 and 744.1 mg/g, respectively. In addition, the structure of activated carbon obtained by adding 1% boric acid into H3PO4 solution contained microcrystalline carbon, which was hard and played a role in enhancing pore structure and the mechanical strength was 85.8%. However, the microcrystalline carbon in the activated carbon obtained by adding 1% saccharin almost transformed graphitization transformation, resulting in soft graphite, thus the strength decreased to 80.1%. The activated carbon with 0.5% sodium citrate had low strength(82.5%) because of its rich pore structure without microcrystalline reinforcement.

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    Effect of Additives on Combustion Characteristics of Straw Briquette Fuel
    Shun JI,Yongfeng QI,Meiting WANG,Ru MA,Panle GE
    2019, 53 (1):  47-53.  doi: 10.3969/j.issn.1673-5854.2019.01.007
    Abstract ( 456 )   HTML ( 239 )   PDF (2675KB) ( 597 )   Save

    It was meaningful to optimize the combustion performance of biomass briquette fuel, which was the main application of biomass energy. The effects of common additives such as CaO, Ca(OH)2, SiO2, Al2O3, urea and fly ash on the release of SO2 and NOx during straw briquette combustion were studied. The results showed that the release of SO2 and NOx was decreased with increasing calcium sulfur ratio and decreasing water content. The catalytic combusion of Al2O3 increased the release of SO2 and NOx, while the sintering of straw and fly ash enhanced the heterogeneous denitrification reaction. Adding SiO2 into briquette fuel was beneficial to the formation of calcium silicate complexes, which could reduce SO2. And the desulfurization and denitrification effects reached the maximum when the dosage of SiO2 was 5%. What was more, when urea was added after combustion for 15 s, the reducing gas produced by the pyrolysis of urea could decrease the release of SO2 and NOx. Moreover, the melting reaction and heterogeneous denitrification reaction were promoted by the increasing temperature, hindering the combustion of coke N, which greatly reduced the release of NOx.

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    Review Comment
    Research Progress of PLA/Cellulose Blend Composites
    Gang WANG,Yi LI,Zhigang LIU,Chengli PEI,Lida WU,Yi TONG
    2019, 53 (1):  54-60.  doi: 10.3969/j.issn.1673-5854.2019.01.008
    Abstract ( 687 )   HTML ( 457 )   PDF (870KB) ( 778 )   Save

    The researches of poly(lactic acid)(PLA)/cellulose, PLA/modified fiber and PLA/cellulose derivatives composites were reviewed. The advantages and disadvantages of the compatibility, dispersion, mechanical properties and degradation characteristics of the composites were introduced. And then, the PLA/EC, PLA/cellulose ester and PLA/carboxymethyl cellulose were presented in detail. This paper provided a reference for the development and application of composites for cellulose/PLA.

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    Progress in Preparation and Application of Hydrophobized Modified Nanocellulose
    Heng ZHANG,Hongkun GAO,Zhe WANG,Xiaolong ZHU,Dongyang LIU
    2019, 53 (1):  61-66.  doi: 10.3969/j.issn.1673-5854.2019.01.009
    Abstract ( 552 )   HTML ( 433 )   PDF (763KB) ( 608 )   Save

    The research progress of hydrophobized modified nanocellulose was reviewed. The hydrophobic modification of nanocellulose was discussed from three aspects: surface adsorption modification, surface hydroxyl chemical modification and graft copolymerization modification. The applications of hydrophobic nanocellulose and its derivatives in emulsion and foam stabilization and in the fields of paper-making, aerogel and membrane materials were introduced. The development was prospected, which provided a reference for the wide application of hydrophobic nanocellulose.

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