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    30 September 2013, Volume 47 Issue 5 Previous Issue    Next Issue
    Effect of Polymerization Degree of PVA on the Mechanical Properties of Alkaline Lignin/Poly (Vinyl Alcohol) Blend Membranes
    XU Guan-hao;REN Shi-xue;FANG Gui-zhen
    2013, 47 (5):  1-6.  doi: 10.3969/j.issn.1673-5854.2013.05.001
    Abstract ( 1034 )   PDF (2459KB) ( 851 )   Save
    With the same addition of alkaline lignin, the blend membranes were fabricated by alkaline lignin and three different polymerization degree of poly (vinyl alcohol) according to the film casting method. The properties of membranes were observed by intelligent electronic universal testing machine, SEM and TG. Also the mechanical properties of the membranes in solvents of different polarities were analyzed. The results showed that alkaline lignin dispersed well in PVA domain and the addition of alkaline lignin improved the mechanical properties of PVA membranes. When the mass fraction of alkaline was 15% and polymerization degree changed from PVA0588 to PVA2488, the tensile strength of blend membranes increased from 35.16 MPa to 48.30 MPa. Which improved 37.37%, and the elongation at break of blend membranes increased from 172.22% to 247.08%, which improved 43.47%. The solvent resistance and thermal stability of the membranes went up with the increase of polymerization degree of poly (vinyl alcohol) and the addition of alkaline lignin.
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    The Control System Design of Conditioning Temperature about Vertical Ring Moulding
    GU Zhi-xin;ZHAO Lin;XU Kai-hong
    2013, 47 (5):  7-12.  doi: 10.3969/j.issn.1673-5854.2013.05.002
    Abstract ( 624 )   PDF (2141KB) ( 623 )   Save
    The feature of material is one of main causes to affact forming quality and energy consumption in the process of briquetting. Research shows that the plastic, strength and wear resistance of material is variable dependent on different temperature. The appropriate temperature can improve the plasticity of material and reduce the abrasion resistance, improve the product quality and reduce energy consumption. The changeful environment condition makes artificially control temperature under ideal condition difficult. The design applies Pt100 temperature sensor to detect the outlet temperature of the modulator. A PLC of integrating PID controller is used to calculate refining temperature and output the control signals to control the DN15-200 proportional valve. Thus the automatic control of temperature is achieved. The corn stalks (10 kg) with moisture content of 18% were used as experimental materials. The simulation experiments were carried out on a control system without temperature equipment and system equipment with temperature control when the product density was set at 1.2 g/cm3. The energy consumption was decreased to 68.7% and the production rate was increased to 36.8% of the system. This could offer helps to promote automation of the straw briquette system and industrialization of products.
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    Preparation and Performance of Cellulose and Hyaluronic Acid, Heparin, Silk Fibroin, Chitin Wet Spinning Biological Composite Fiber
    ZHANG Min;XU Xiao-ling;MENG Xiao-rong;GU Li-min
    2013, 47 (5):  13-18.  doi: 10.3969/j.issn.1673-5854.2013.05.003
    Abstract ( 619 )   PDF (2682KB) ( 684 )   Save
    Each spinning solution of cellulose was mixed with hyaluronic acid (HA), heparin (Hep), silk fibroin (SF) and chitin (N-ACS) in aqueous NaOH solution respectively at room temperature, They were sprayed into 10% sulfuric acid containing 40%-43% of ammonium sulfate through a spinneret (0.1 mm in hole diameter). Novel white blend biofilaments were obtained in 75%-98% yield. The flexibility of these biology fiber composites was also good. FT-IR spectra indicated that physical adsorption and hydrogen bond interaction existed between the components of composite fibers. A small amount of HA, Hep, SF, and N-ACS in composites would increase the flexibility of composite fibers. The cellulose-silk fibroin fiber has the best mechanical properties when the mass fraction of the silk fibroin was 10%. Its size was 9.9 denier, its tenacity value was 1.08 g/denier and its elongation value was 35%. The stripe, scaly, filling, and the evenly coated structure on the filaments surface were examined by SEM observation. It indicated that certain compatibility existed on the composite fibers. The diameter of composite fibers was 19-55 μm and the density was 0.1-0.36 denier/μm.
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    Study on Preparing Longifolene from Heavy Turpentine Catalyzed by a New Type of Solid Super Acid
    XU Rong-sheng
    2013, 47 (5):  19-22.  doi: 10.3969/j.issn.1673-5854.2013.05.004
    Abstract ( 629 )   PDF (946KB) ( 668 )   Save
    A novel solid super acid with the composition of S2O82-/ZrO2-TiO2 added with Ce4+ was prepared by precipitation and impregnation. Then, the solid super acid was applied to purify longifolene from heavy turpentine oil via a catalytic conversion reaction. The experimental results showed that the catalyst had high catalytic activity for the isomerization reaction. The optimum conditions for the preparation of the catalyst are as follows: concentration of (NH4)2S2O8 1 mol/L and calcination temperature 600 ℃. With the addition of Ce4+, it can slow the components loss and improve the catalytic stability. Ce-S2O82-/ZrO2-TiO2 has the best catalytic activity when the mass fraction of CeO2 is 2%. The optimum conditions for the conversion of heavy turpentine are as follows: ratio of solid super acid to heavy turpentine in mass 3.5%, conversion temperature 150 ℃ and reaction time 4 h. The conversion ratio of caryophyllene is 99.1%. And from the product, longifolene was prepared through rectification in purities (GC) of 80%, 85% and 90%, respectively.
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    Synthesis of Cardanol Modified Phenolic Resol Resin and the Properties of Its Foam
    LIU Rui-jie;TAN Wei-hong;ZHOU Yong-hong;HU Li-hong;
    2013, 47 (5):  30-34.  doi: 10.3969/j.issn.1673-5854.2013.05.006
    Abstract ( 923 )   PDF (1449KB) ( 640 )   Save
    Phenolic resin was modified by cardanol that replaced part of phenol. The expandable phenolic resol resin was prepared. The influences of the cardanol substitution amount on the properties of phenolic resol resin and phenolic foam were investigated. Using the IR spectra and thermo gravimetric analyzer, the structure and thermal stability of resin were analyzed. The mechanical property was studied by the electronic universal testing machine. The results showed that the resin viscosity was 4 650 mPa·s, free phenolic content decreased from 6.72% to 5.45%, free formaldehyde content decreased from 1.17% to 0.68% and the maximal compressive strength of phenolic foam reached 0.20 MPa when the cardanol substitution amount was 10%. But the thermal stability of phenolic resin and the flame retardant of phenolic foam were reduced.
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    Heat Effect of Biomass and Biomass Components Slow Pyrolysis
    HU Yi-ming;JIANG Jian-chun;SUN Yun-juan;YANG Zhong-zhi
    2013, 47 (5):  23-29.  doi: 10.3969/j.issn.1673-5854.2013.05.005
    Abstract ( 833 )   PDF (2089KB) ( 716 )   Save
    Accelerating Rate Calorimeter (ARC) has been utilized to investigate biomass components and several types of biomass pyrolysis. The results showed that, pyrolysis under constant input power, cellulose had a exothermic peak in the range of 256.2-279.2 ℃ and generated heat 673.9 J/g. The residue yield was 51.8%. Xylan also had a sharp exothermic peak at 219.8-253.7 ℃, released heat 873.3 J/g. The residue yield was 68.7%. The heat flow curve of lignin pyrolysis showed a endothermic trend between 133.3-292.2 ℃ and absorbed heat 340.1 J/g. The residue yield was 80.4%. During biomass pyrolysis, two consequent exothermic peaks have been found in the heat flow curves. These two peaks are caused by hemicellulose and cellulose pyrolysis respectively. The endothermic trend of lignin has also been detected as well. Each biomass has released different amount of heat, but the initial heat releasing temperature is around 190 ℃. The first peak temperature is around 220 ℃ and the second peak is concentrated at around 255 ℃.
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    Extraction Technique of Eucommia Gum from Residue of Eucommia ulmoides Leaves
    XIE Xiao-ting;LU Bo-qiong;WANG Zi-bo;DING Lai-xin
    2013, 47 (5):  35-39.  doi: 10.3969/j.issn.1673-5854.2013.05.007
    Abstract ( 718 )   PDF (1198KB) ( 699 )   Save
    Residue of Eucommia ulmoides leaves, after being processed for pharmaceutical ingredients, was used to extract Eucommia gum. Both of solvent extraction of Eucommia gum, with pretreatment of E. ulmoides leaf residue by alkali hydrolysis and enzymatic hydrolysis separately, and direct extraction were studied. The optimum process condition was that: E. ulmoides leaf residue was mixed with n-hexane by a material to solvent ratio of 1:20 (g:mL), reflux extraction was applied at a high temperature for 2 h. Filtrate was put in freezer for 1 h at -20 ℃ for cooling crystallization, and then vacuum filtered and naturally dried to obtain the product of light green Eucommia gum. The yield was 4.42%. White Eucommia gum was obtained after multiple times of refining by acetone. The infrared spectrum of white Eucommia gum was measured, It was identified as trans-1, 4-polyisoprene (TPI).
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    Synthesis of p-Menthane-1, 2, 4-Triol and Its Herbicidal Activity for Barnyard Grass
    HUANG Dao-zhan;WANG Xiao-shu;ZHU Shou-ji;YAN Fang;LAN Hong-yun;BAI Li-juan
    2013, 47 (5):  40-44.  doi: 10.3969/j.issn.1673-5854.2013.05.008
    Abstract ( 698 )   PDF (1156KB) ( 665 )   Save
    Oxidation of 4-terpineol with 30% H2O2 catalyzed by quaternary ammonium peroxotungsto-phosphate catalyst[π-C5H5(CH2)11CH3]3PW4O32 in 1,2-dichloroethane gave p-menthane-1,2,4-triol. The product was easily separated as a white crystalline powder by filtration and structurally identified by means of EA, IR, 1H NMR and 13C NMR. Under the optimal reaction conditions, i.e. 4-terpineol 12.3 mmol, 1,2-dichloroethane 5 mL, molar ratio of hydrogen peroxide to 4-terpineol 1.25:1, mass percentage of catalyst to 4-terpineol 2.98%, reaction temperature 50 ℃, reaction time 1.5 h, the conversion rate of 4-terpineol and yield of p-menthane-1,2,4-triol were 99.8% and 58.0%, respectively. The purity of product can reach more than 98%. The preliminary herbicidal assay had that p-menthane-1,2,4-triol had an obvious post-emergence inhibitory effect against shoot growth and root elongation of barnyard grass (Echinochloa crusgalli L.). The percentage inhibition of root growth and shoot elongation at 10 mmol/L concentration in herbicidal test were 100% and 81.4%, respectively.
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    Preparation of Levulinic Acid and Analysis of Its Application Prospect
    WANG Yi-gang;NIE Xiao-an;LIU Zhen-xing
    2013, 47 (5):  45-50.  doi: 10.3969/j.issn.1673-5854.2013.05.009
    Abstract ( 797 )   PDF (1482KB) ( 676 )   Save
    In this paper, the preparation method of highly active platform compound levulinic acid and its application prospects were reviewed. The characters and reference of preparing levulinic acid from different raw materials were analyzed. The effects of different catalysts and pretreatment methods on the yield of levulinic acid were discussed. At last, the application prospects of levulinic acid on different fields were prospected.
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    Research Advance in Solid Catalysts for Biodiesel Production
    SI Zhan;JIANG Jian-chun;WANG Kui
    2013, 47 (5):  51-56.  doi: 10.3969/j.issn.1673-5854.2013.05.010
    Abstract ( 848 )   PDF (1524KB) ( 681 )   Save
    The article briefly introduces the biodiesel and its preparation methods, we also mainly reviews the applications of solid catalysts for biodiesel production in recent years. In addition, the paper has looked into the future of the solid catalysts, as well.
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