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    25 October 2016, Volume 36 Issue 5 Previous Issue    Next Issue
    Synthesis and Characterization of 3-(2'-Hydroxybenzylidene) Nopinone and Its Acid-base Indicator Performance
    YANG Jin-lai, ZHANG Yan, RUI Jian, SUN Nan, XU Xu, YANG Yi-qin, WANG Shi-fa
    2016, 36 (5):  1-7.  doi: 10.3969/j.issn.0253-2417.2016.05.001
    Abstract ( 721 )   PDF (1007KB) ( 553 )   Save
    Nopinone was first synthesized by oxidation reaction of β-pinene. 3-(2'-Hydroxybenzylidene)nopinone was further synthesized by aldol condensation reaction of nopinone and salicylaldehyde and the process conditions were optimized by single factor and orthogonal experiment. The optimal condensation reaction conditions were determined as follows:1.43 g nopinone, tert-butyl alcohol (30 mL) as the solvent, potassium tert-butoxide (2.5 g) as the catalyst, the molar ratio of nopinone and salicylaldehyde 1:1.2 and the reflux reaction time 2 h. Under these condition, the yield of 3-(2'-hydroxybenzylidene)nopinone was 79.46%. The structure of 3-(2'-hydroxybenzylidene)nopinone was characterized and confirmed by MS, IR, NMR, and X-ray diffraction, and the crystal was in monoclinic system with P212121 space group. The acid-base indicator performance of 3-(2'-hydroxybenzylidene)nopinone was investigated. The results showed that the final color was orange and the measured concentration of hydrochloric acid was 0.259 6 mol/L with the RSD of 0.089%. When this compound was used to titrate hydrochloric acid standard solution (0.257 4 mol/L). As an acid-base indicator, 3-(2'-hydroxybenzylidene)nopinone was better than phenolphthanlein because of its high sensitivity and small deviation.
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    Multi-stage Enzyme Hydrolysis of Steam-explored Corn Stover
    WANG Yan-yun, WU Kai, YANG Jing
    2016, 36 (5):  8-14.  doi: 10.3969/j.issn.0253-2417.2016.05.002
    Abstract ( 588 )   PDF (1019KB) ( 694 )   Save
    With the steam-explored corn stover as the substrate, the effects of multi-stage hydrolysis and the reuse of β-glucosidases via ultrafiltration technique on enzymatic hydrolysis yield were investigated. The analysis results indicated that the removal of cellobiose and glucoseat each stage was benefit to improve the cellulase activities, the hydrolysis efficiency was enhanced and less hydrolysis time was obtained. Higher hydrolysis yield (70.16%) was achieved as three-stage (6+6+12) h hydrolysis was used in 24 h in contrast to a 62.84% yield in 72h for one-stage hydrolysis. The steam-explored corn stover was composed by 23% crystalline region and 77% amorphous region. Two diffraction peaks of substrate at diffraction angle of 16° and 22° were prominent after the three-stage (6+6+12) h hydrolysis, and the diffraction intensity increased. The ultrafiltration technique with the 30 ku membrane was employed to recover the β-glucosidase. The glucose yield during the first round of hydrolysis was 92.71%, and the β-glucosidase recovery rate was 98.87%. During the 8th round of hydrolysis, the glucose yield and the β-glucosidase recovery rate were 90.87% and 95.25%, respectively.
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    Synthesis and Spectral Properties of Chiral Isomers of Dibornyl Oxalate
    YUAN Xiao-min, CHEN Jin-feng, YI Xiao-qing, ZHAO Zhen-dong, ZHANG Ping-hui, CHEN Yu-xiang, XU Shi-chao
    2016, 36 (5):  15-22.  doi: 10.3969/j.issn.0253-2417.2016.05.003
    Abstract ( 628 )   PDF (1829KB) ( 496 )   Save
    Dibornyl oxalates with different optical activity were synthesized by indirect esterification method from different chiral borneol with oxalyl chloride, and the target products could be easily purified to 99.9% (GC) through recrystallization with alcohol. The composition of the synthesized dibornyl oxalates were analyzed by chiral high-performance liquid chromatography (HPLC), and it was proved that there were (-)-dibornyl oxalate, mesomer and (+)-dibornyl oxalate in the synthesized racemic dibornyl oxalate, and the mass ratio was nearly 1:2:1. The location of hydrogen and carbon atoms in (-)-dibornyl oxalate was determined by means of 1H-1H COSY, HSQC and HMBC, and the spectra of different chiral dibornyl oxalate were contrasted including GC-MS, IR, 1H NMR and 13C NMR. Furthermore, the synthetic racemic dibornyl oxalate was compared with the mixture of equal (+) and (-) dibornyl oxalates. The results showed that the spectral properties of (+), (-) and racemic dibornyl oxalate were similar, however these oxalates could be distinguished via optical activity. The mesomer, which contained in the synthesized racemic dibornyl oxalate from the reaction of racemic borneol and oxalyl chloride, owned different nuclear magnetic chemical environment and spectral properties of the carbon and hydrogen atoms on both sides. This reflected in the different chemical shifts of the hydrogen atoms on 8-and 8'-, 3-and 3'-, and the carbon atoms on 1-and 1'-, 3-and 3'-as well as 11-and 11'-positions.
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    Preparation and Performance of ZrC Woodceramics Obtained by Polymer Precursor Conversion
    WU Hai-tang, ZHENG Ji-lu, ZHANG Jun-hua, HUANG Xiao-hua
    2016, 36 (5):  23-29.  doi: 10.3969/j.issn.0253-2417.2016.05.004
    Abstract ( 519 )   PDF (1282KB) ( 481 )   Save
    Biomorphic ZrC woodceramics were fabricated by high temperature pyrolysis of the precursor of infiltrated organic zirconium-contained polymer(PZC) using pine charcoal as template under argon. The phase change, composition and microstructure of resulting ZrC woodceramics, as well as the conversion mechanism of wood to ZrC woodceramics, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques, respectively. The effects of heat treatment temperature and weight gain of charcoal/PZC hybrid material on the apparent porosity and mechanical properties of the ZrC woodceramics were analysed. The results indicated that the impregnant was firstly decomposed to ZrO2, and then reacted with carbon in the cellular wall to form ZrC at 1 400℃. The cellular morphology of biocarbon template was retained well in the resulting ceramics consisting of cubic ZrC and amorphous carbon. The apparent porosity of ZrC woodceramic increased with the increase of heat treatment temperature and decreased with the increase in weight gain of charcoal/PZC hybrid material. Moreover, it was found that the mechanical properties of ZrC woodceramic were enhanced significantly when the weight gain and heat treatment temperature increased. The ZrC woodceramic prepared at 1 400℃ from charcoal/PZC hybrid material with the weight gain of 278% exhibited good mechanical properties, and its flexural strength and fracture toughness were 158 MPa and 1.8 MPa·m1/2, respectively.
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    Synthesis of α-Brominated Isolongifolenone with Chirality
    DING Zhi-bin, SUN Nan, ZHANG Qi, CAO Xiao-qin, XU Xu, WANG Shi-fa
    2016, 36 (5):  30-36.  doi: 10.3969/j.issn.0253-2417.2016.05.005
    Abstract ( 642 )   PDF (825KB) ( 525 )   Save
    The bromo-reaction of (2R, 4aS)-isolongifolenone to α-brominated isolongifolenone was investigated. Isolongifolenone was reacted with copper bromide in ethyl acetate, and the two isomerides, (2R,4aR,6R)-(+)-6-Br-isolongifolenone ([α]D25+81°) and (2R,4aR,6S)-(-)-6-Br-isolongifolenone ([α] D25-58°), were obtained by purification with preparative liquid chromatography. The structures of the two compounds were characterized by 1H NMR,FT-IR,GC-MS, specific rotation, and singal crystal X-ray diffraction. Furthermore, the effects of preparing conditions on the products were also explored. It was shown that (2R,4aR,6S)-(-)-6-Br-isolongifolenone could be obtained through a selective bromination of isolongifolenone by using ethanol as solvent and copper bromide as the reaction reagent. The optimum conditions of preparing (2R,4aR,6S)-(-)-6-Br-isolongifolenone were the molar ratio of copper bromide/isolongifolenone 3:1, ethanol dosage 60 mL, reaction time 3 h and reaction temperature 78℃. Under the foresaid conditions, the reaction selectivity and the yield of (2R,4aR,6S)-(-)-6-brominated isolongifolenone were 93% and 88%, respectively.
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    Preparation and Characterization of Oil Absorbent Material Derived from Corn Stalk
    LIU Xiao-hui, CAO Ya-feng, LI Yuan, LIU Zhao-li, TAN Feng-zhi
    2016, 36 (5):  37-44.  doi: 10.3969/j.issn.0253-2417.2016.05.006
    Abstract ( 913 )   PDF (3071KB) ( 510 )   Save
    By using raw corn stalk (RCS) as staring material, PCS was pretreated with ammonia water and then employed to perform esterification with acetic anhydride. Thus, the oil absorbent materials derived from raw corn stalk (ECS) was obtained. The effect of esterification condition on the performance of oil absorption was also investigated. The results indicated that the oil absorbency of the RCS and PCS (pretreated for 6 h) to 0# diesel were 1.90 and 4.43 g/g, respectively. The oil absorbency of the obtained ECS material could be 9.03 g/g which was prepared under the following esterification conditions:acetic acid as solvent, m(acetic acid):m(acetic anhydride)=1, m(corn stalk):m(liquid mixture)=1:15,4.5% H2SO4 as catalyst (base on the mass of PCS), reaction temperature 110℃ and reaction time 5 h. The obtained ECS displayed a remarkably increase in hydrophobicity and floating ability after esterification modification. The RCS, PCS and ECS were analyzed and characterized by BET, FT-IR, XRD, SEM. The results showed that the esterification reaction was carried out smoothly. the corn stalk after esterification modified presents amorphous state. and ECS even exhibits mesoporous structure. Additionally, the appearances of mesoporous structure and rough morphology were helpful to improve the oil absorbency and floating ability of the ECS.
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    Dissolution Performance of Lignin in Triazole-bazed Ionic Liquids
    WANG Ya-nan, LIU Shi-wei, LI Lu, YU Shi-tao
    2016, 36 (5):  45-52.  doi: 10.3969/j.issn.0253-2417.2016.05.007
    Abstract ( 795 )   PDF (1231KB) ( 508 )   Save
    Three triazolyl ionic liquids, i.e., 1-butyl-3-methylimidazolium triazole([Bmim] tr), N-methyl-N-n-butylmorpholinium triazole([Bmmo] tr), N-n-butylpyridinium triazole([Bpy] tr), were synthesized. It was found that ionic liquid[Bmim] tr had good solubility performance for lignin dissolution,and the solubility was 58.61 g at 55℃ under microwave heating. The chemical structure, molecular weight, crystalline and morphology of regenerated lignin from microwave treatment were characterized by HSQC, FT-IR, GPC, XRD and SEM. The results indicated that microwave heating trends to cleavage hydrogen bonds and β-O-4' linkages, which accelerated the dissolution of lignin. And the basic structural unit of lignin was not destroyed in the dissolution process. The analysis showed that the dissolution mechanism of lignin in ionic liquid was the hydrogen bond damage and fracture of β-O-4' connection structure.
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    Preparation of Carbon Foams with High Compressive Strength Derived from Phenolic Resin
    LI Xue-mei, LIU Shou-qing, HUANG Yuan-bo, YANG Xiao-qin, ZHENG Yun-wu, HUANG Gui-xiang, ZHENG Zhi-feng
    2016, 36 (5):  53-60.  doi: 10.3969/j.issn.0253-2417.2016.05.008
    Abstract ( 745 )   PDF (1633KB) ( 613 )   Save
    Carbon foams were synthesized by foaming method with self-made phenolic resin as precursor. The effects of the foaming conditions and carbonization conditions on microstructure, phase composition and mechanical properties of carbon foams were investigated. The results showed that phenolic resin foams should be heated in a low heating rate(1℃/min) at 200-650℃ during carbonization process. Carbon foams obtained under carbonization temperature 900℃ were mainly amorphous carbon and sodium chloride crystal, which were proved by XRD analysis. The SEM images revealed that the surfactant (Tween 80) had a significant influence on the distribution of bubbles in carbon foams, and the amounts of foaming agent(n-hexane) mainly affected the number of bubbles and pore size, while the amounts of curing agent(hydrochloric acid) influenced the pore size significantly. The optimum preparation conditions of carbon foams were curing agent 3%, surfactant 6% and foaming agent 6% (based on phenolic resin weight), respectively. The resultant carbon foam had pore size ranged of 50-150 μm with uniform structure and the thinner hole-wall. It also had a apparent density of 0.276 g/cm3, specific surface area of 137.9 m2/g, and the compressive strength of 11.1 MPa.
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    Synthesis and Phase Separation Phenomena of Cardanol Diethers-Mannich Base Curing Agent
    SONG Jian, LI Mei, LI Shou-hai, HUANG Kun, XIA Jian-ling
    2016, 36 (5):  61-67.  doi: 10.3969/j.issn.0253-2417.2016.05.009
    Abstract ( 923 )   PDF (1288KB) ( 745 )   Save
    The cardanol diethers (CDE) was obtained from Williamson etherification of cardanol(CD) and 1,3-dibromopropane. Then the cardanol diethers-Mannich baseas curing agent (MBCDE) for epoxy resins was prepared from the Mannich reaction of CDE, paraformadehyde and diethylenetriamine. The chemical structure was confirmed by FT-IR and 1H NMR. N-Aminoethylpiperazine (AEP) was chose as a control to investigate the toughening properties of MBCDE. Thermogravimetric analysis (TGA), scanning electronic microscopy (SEM) and mechanical properties of the cured epoxies were also conducted to investigate the properties of the bisphenol A epoxy resin (DGEBA) cured by two curing agents. The TGA results showed that the maximum decomposition temperature of MBCDE was 351.6℃ and the sample had good thermal stability. The impact strength of cured AEP/DGEBA was 3.641 J/m, while the cured 80% MBCDE sample had an impact strength of 5.155 J/m, which was improved by 41.6%. SEM results indicated that there was phase seperation in the cured materials contained MBCDE.
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    Preparation, Characterization and Micro-structure of Anionic Polysiloxane Modified Terpene-based Epoxy Resin Polyol Dispersion
    LIU Di, WU Guo-min, LIU Gui-feng, KONG Zhen-wu
    2016, 36 (5):  68-74.  doi: 10.3969/j.issn.0253-2417.2016.05.010
    Abstract ( 639 )   PDF (1397KB) ( 585 )   Save
    Terpene-based epoxy resin polyol (T-N) was prepared via the reaction of terpene-based epoxy resin(TME) and neopentyl glycol(NPG). Then the T-N was modified with hydroxypropyl terminated polysiloxane(HTP), 2,4 tolylene diisocyanate(TDI) and 2,2-bis (hydroxymethyl) propionic acid(DMPA) to obtain the anionic polysiloxane-modified terpene-based epoxy resin polyol (T-N-S) dispersion. The chemical structure of the T-N-S was characterized by FT-IR and NMR. The micro-morphology of T-N-S was determined by transmission electron microscopy (TEM) and particles size measurement. And the effects of reaction condition and siloxane content on the stability and micro-structure of the polyol dispersion were studied. T-N-S dispersion was obtained at the conditions of DMPA and TDI were mixed with the molar ratio 1:2 in the presence of solvent acetone (the amount of solvent was 1.5-2 times based on the reactants mass) and refluxed at 56℃ for 3 h. Then HTP and T-N were added in to the reaction and continued to feflux for 4 h. The obtained T-N-S dispersion showed good stability and the particle size of the dispersion ranged from 100 to 300 nm when the dosage of HTP was 3%-12% of T-N by weight.
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    Selectively Removing Lignin from Pre-hydrolysis Liquor by Combined CaO/PAC Method
    ZHOU Dan-dan, HOU Qing-xi, LIU Wei, FENG Qing
    2016, 36 (5):  75-80.  doi: 10.3969/j.issn.0253-2417.2016.05.011
    Abstract ( 570 )   PDF (777KB) ( 473 )   Save
    A noval process, based on the combination of CaO and polyaluminium chloride (PAC) flocculation, was developed to selectively remove lignin from pre-hydrolysis liquor (PHL). The selective removals of lignin by using acidification, alkalization and combined process were investigated and the mechanism of removal lignin by PAC was investigated. The results showed that the maximum removal rates (poplar chip 15.68% and wheat straw 18.76%) of acidification were obtained at pH value of 1.5 and the removal rates of CaO treatment reached the maximum (poplar chip 33.33% and wheat straw 30.67%) as adjusting the pH value with CaO to 12. After the CaO treatment for the hydrolysate, both the removal rate and selectivity of lignin were higher than those of acidification treatment. Using CaO to adjust pH to 10 and then adding PAC to 36 mmol/L, the removal rate of lignin in pre-hydrolysis liquor reached the maximum, the numbers were 50.59% and 49.17% for poplar chips and wheat straw, respectively. Meanwhile, the selectivites were the best, represents 86.57% and 82.76% for poplar chips and wheat straw, respectively.
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    Preparation and Characterization of Lignocellulose Gel from Soybean Stem/LiCl/DMSO Solution
    LIU Zhu-lan, CAO Yun-feng, WANG Zhi-guo, XIA Jian-yu, SU Chen
    2016, 36 (5):  81-88.  doi: 10.3969/j.issn.0253-2417.2016.05.012
    Abstract ( 993 )   PDF (2018KB) ( 590 )   Save
    The lignocellulose gels with mesopore structures were prepared via dissolving ethylenediamine (EDA) pretreated soybean stem in 8% LiCl/DMSO solvent system and gelation in ethanol. The results showed that the delignification could affect the pore strucutre, thermal stability and swelling ability of lignocellulose gels. As the delignification went on, the thermal stability as well as the liberation degrees of cellulose, hemicellulose and lignin increased, and the char yield decreased. Meanwhile, the denser fibril network structure with smaller mesopore and higher specific area were generated because of the separation of carbohydrates and lignin as well as the increasing crystallinity of lignocellulose. Then the swelling ability was also dramatically affected. For the gel prepared from soybean stem with 2 h of delignification, the thermal decomposition temperature was 230℃, the char yield was 15%, the specific area and mesopore size were 64.29 m2/g and 17.813 nm, respectively, and its equilibrium swelling ratio at 15℃ was 2 126.79%. Within contrast to the gel made form soybean stem without delignification, the thermal decomposition temperature and specific area increased by 30℃ and 11.02 m2/g, respectively. The char yield and mespore size decreased by 47.7% and 2.468 nm, while the equilibrium sewlling ratio reduced by 16.6%.
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    Effect of Sulfite Pretreatment on Hydrolysis Efficiency of Sugarcane Bagasse
    LIU Zhi-jia, DONG Yi-fan, LAN Tian-qing
    2016, 36 (5):  89-94.  doi: 10.3969/j.issn.0253-2417.2016.05.013
    Abstract ( 633 )   PDF (827KB) ( 579 )   Save
    To overcome the anti-degradation of sugarcane bagasse, sulfite pretreatment (SPORL) was used and the effects of sodium bisulfite concentration on the physicochemical characteristics, the sulfonic acid group on the surface(sulfonation degree) and hydrolysis efficiency of sugarcane bagasse were investigated, and the effect of sulfonation degree on hydrolysis efficiency of bagasse was further studied. The results revealed that different sodium bisulfite concentration had no significant influences on the crystrallinity index (ICr) of bagasse and bagasse samples treated by SPORL had more crystalline cellulose and less hemicellulose. Besides, 50 g oven bagasse with 1:8 solid-liquid ratio was treated by adding 8% sodium bisulfite(based on the dry bagasse) at 160℃ for 30 min and 131.73 μmol/g sulfonic group was obtained. The hydrolyses of bagasse with different degree of sulfonation were conducted at 50℃ for 72 h as 7.5 FPU/g dry bagasse (based on 2% dry bagasse). The results demonstrated that the enzymatic efficiency increased with the increase of degree of sulfonation and the highest hydrolysis efficiency of holocellulose was 83.76%. The study indicated that the hydrolysis efficiency of bagasse was positively related to sulfonic group content in bagasse and had no significant relationship with crystallinity degree of bagasse. Low-pH SPORL could remove most hemicellulose in bagasse, and the anti-degradation of bagasse was overcome. Finally, the enzymatic hydrolysis of lignocellulose was enhanced as well.
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    Preparation and Properties of Carbamic-oxazolindnone Double Cross-linking System Based on Castor Oil
    MAO Wei, LI Shou-hai, YANG Xue-juan, SONG Jian, WANG Mei, XIA Jian-ling
    2016, 36 (5):  95-100.  doi: 10.3969/j.issn.0253-2417.2016.05.014
    Abstract ( 683 )   PDF (1271KB) ( 510 )   Save
    Epoxidized castor oil (ECO) was synthesized via epoxidation of castor oil (CTO). Then the prepared ECO was cured with toluene diisocynate (TDI) at 80℃ or 150℃ to obtain two kinds of cured cross-linking materials, and their molecular structures and comprehensive properties were studied. The results showed that the tensile strength, hardness and glass transition temperature of these two cured materials were improved significantly. Thermogravimetric analysis showed that all cured materials owned good thermal stability and the heating initial decomposition temperatures of cured materials were above 280℃. And the cured material obtained at 150℃ possessed typical carbamic-oxazolidone double cross-linking molecular structure.
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    Pore Structure Analysis and Methane Adsorption of Self-form Granular Activated Carbon by Phosphoric Acid Activation
    LIN Guan-feng, JIANG Jian-chun, WU Kai-jin, CAI Zheng-han, SUN Kang, LU Xin-cheng
    2016, 36 (5):  101-106.  doi: 10.3969/j.issn.0253-2417.2016.05.015
    Abstract ( 564 )   PDF (796KB) ( 622 )   Save
    Preparation of granular activated carbon (GAC) by phosphoric acid activation from fir wood powder were analyzed without any other binder. The activation process,pore structure and methane adsorption of the synthesized GAC were also tested.The results showed that with activation temperature increasing,the adsorption capability of the GAC rose first and fell later, the abrasion strength was steadily improved and the optimum temperature was 450℃. With increasing of impregnation ratio,the adsorption capability of the GAC increased,however the abrasion strength decreased.The analysis of nitrogen adsorption isotherm and mercury injection method showed that the GAC possessed a large number of micropore,mesopore and macropore. The increase of impregnation ratio was favorable for the increase of pore volume, but the bulk density and apparent density decreased.The methane adsorption value of the unit mass and the unit volume of the GAC reached the maximum 125.6 mL/g and 115.2 L/L with the impregnation ratio of 1.25, activation temperature 450℃ and pressure 3.4 MPa.
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    Deflaking Characteristics of Rice Straw Alkali-oxygen Pulp
    SHAO Si-cheng, WU Chu-zhu, CHEN Ke-li
    2016, 36 (5):  107-112.  doi: 10.3969/j.issn.0253-2417.2016.05.016
    Abstract ( 628 )   PDF (1190KB) ( 569 )   Save
    The effects of deflaking on the drainability, fiber morphology as well as the ash and silica contents of rice straw alkali-oxygen pulp were investigated. The results indicated that the beating degree of the pulp without non-fibrous cells fell around 10°SR. Deflaking played a negative role in the drainability of the pulp. However, the development trend of the beating degree originated from deflaking depended marginally on non-fibrous cells, but greatly on pulp fibers. This resulted from the fibrous deformation sensitive to deflaking. On the other hand, it was found that owing to the presence of a large quantity of non-fibrous cells, the deflaking could increase the content of fines component in the straw pulp with non-fibrous cells markedly by 3.7 percentage points. Also, it presented an ever-decreasing tendency in terms of kink index, curl index, width and silica proportion in its ash. This was opposite to the behavior of the pulp without non-fibrous cells.
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    Aqueous Two Phase Extraction of Resveratrol and Emodin in Fruits of Polygonum cuspidatum Assisted by Microwave Procedure Controlled Temperature and Pressure
    BU Xiao-ying, YAO Shu-feng, XU Xin-jun
    2016, 36 (5):  113-119.  doi: 10.3969/j.issn.0253-2417.2016.05.017
    Abstract ( 561 )   PDF (1247KB) ( 571 )   Save
    Microwave procedure controlled temperature-pressure assisted ethanol-ammonium sulfate aqueous two-phase extraction was used to extract the resveratrol and emodin from Polygonum cuspidatum fruits. The effects on extraction rate and purity of resveratrol and emodin were compared by three extraction methods, microwave assisted extraction, microwave-assisted aqueous two-phase extraction and the above mentioned. The chemical structure was determined using Infrared (IR) spectroscopy. The aqueous two-phase system was made by solid-to-solvent ratio 1:20 (g:mL) and ethanol-(NH4)2SO4 with phase separation coefficient of 0.5. Microwave procedure to controll temperature-pressure conditions were divided into 5 stages, i.e., room temperature, 40, 50, 60 and 70℃, and the corresponding control pressure 137.9, 344.75, 689.5, 1 034.25 and 1 379 kPa. Each upgrading microwave lasted 1.2 min and the interval was 5 min. The results showed that under these conditions, the extraction rate of resveratrol and emodin from the fruits of polygonum cuspidatum were 0.694% and 2.067% with purify of 82.68% and 87.25%, respectively. This significantly improved the extraction rate of resveratrol and emodin from the fruits of P. cuspidatum. This also maintained the biology active and had excellent stability, excellent repeatability, high-precision and high-recovery compared with other two methods. Meanwhile, the method simplified the process of separation and purification and reduced production costs, so it was suitable for the extraction of resveratrol and emodin in the fruits of P. cuspidatum.
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    Chemical Composition and Lignin Distribution of Salix integra
    CUI He-shuai, YANG Shu-min, LIU Xing-e, MA Jian-feng, TIAN Gen-lin
    2016, 36 (5):  120-126.  doi: 10.3969/j.issn.0253-2417.2016.05.018
    Abstract ( 684 )   PDF (1599KB) ( 652 )   Save
    Chemical composition and their variation patterns along stem height, and lignin distribution of Salix integra were investigated using the traditional determination of chemical composition and confocal laser scanning microscope (CLSM). The results showed that the contents of the extractives of 1% NaOH, hot-water, cold-water, benzene-ethanol, the holocellulose, α-cellulose, acid-insoluble lignin, acid-soluble lignin, pentosan and ash were 32.11%, 10.85%, 7.11%, 3.27%, 70.46%, 35.50%, 20.18%, 4.50%, 15.51% and 0.90%, respectively. The variation of each composition was significant in different parts except α-cellulose and pentosan. It was also observed that the lignin distribution was heterogeneous. The lignin concentration in vessel was higher than that in fiber and ray, and the lignin concentration in cell wall of fiber followed a decreasing order of the cell corner, the complex middle lamella and the secondary cell wall.
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    Preparation of Ethyl Levulinate by Pressurized Liquefaction of Wheat Straw
    GUAN Qian, JIANG Jian-chun, XU Jun-ming, WANG Kui, FENG Jun-feng
    2016, 36 (5):  127-132.  doi: 10.3969/j.issn.0253-2417.2016.05.019
    Abstract ( 647 )   PDF (1075KB) ( 537 )   Save
    The liquefaction experiments were carried out using wheat straw as raw material, concentrated sulfuric acid as catalyst and ethanol as solvent. The composition of liquefied product was analyzed, and the effects of different conditions on conversion rate and yield of the target product ethyl levulinate (EL) were examined. The results showed that optimum liquefaction conditions was catalyst dosage 10%, reaction temperature 190℃, reaction time 60 min, and liquid solid ratio of 18:1 (g:g, the same below). Under the circumstances, the yield of EL was up to 18.11% with liquefaction ratio of 75%. Degradation of wheat straw during the reaction was confirmed by infrared spectroscopic analysis. The liquid product contained aldehydes, ketones, esters, phenols, acids, and some other oxygenates. It was found that cellulose was converted into intermediate, such as glucose, glucoside, ethoxymethyl furfural, et al. They can be further transformed into ethyl levulinate.
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    Research Progress on Cell Wall Structure and Main Chemical Components of Cork
    SONG Xiao-zhou, YUAN Yi-dan, ZHANG Qiang, ZHAO Jing-feng
    2016, 36 (5):  133-138.  doi: 10.3969/j.issn.0253-2417.2016.05.020
    Abstract ( 761 )   PDF (1628KB) ( 691 )   Save
    The morphological characteristics of cork cell were introduced. The research achievements of cell wall structure and main chemical components of cork from home and abroad were reviewed. Cork cell wall has clear layered structure. An important characteristic of cork cells wall is the existence of folds. The channel structures of plasmodesmata are found in the cork crossing adjacent cell walls. The main chemical compositions of cork cell walls are suberin, lignin, polysaccharides, extractives and ash. The contents, monomers extraction and identification are summarized. The research ideas of cork cell walls are given.
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