Table of Content

25 April 2020, Volume 40 Issue 2 Previous Issue   

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Research Progress in Wood Adhesives Yufeng MA,Xuan'ang GONG,Chunpeng WANG 2020, 40 (2):  1-15.  doi: 10.3969/j.issn.0253-2417.2020.02.001 Abstract ( 1429 )   HTML ( 1277290968 )   PDF (1668KB) ( 1438 )   Save The consumption of wood adhesive in China is huge. However, the main wood adhesive based on formaldehyde is still prevalent. In recent years, environment friendly adhesives such as non-formaldehyde adhesives and biomass adhesives have developed rapidly. Herein, the recent research and application of wood adhesives including urea-formaldehyde resin adhesives, phenolic resin adhesives, melamine-formaldehyde resin adhesives, protein adhesives, lignin adhesives, starch adhesives, tannins adhesives, isocyanate adhesive, emulsion adhesives and pyrolysis biological oil adhesives were reviewed. The development trend and the research direction of wood adhesives were also prospected. Figures and Tables | References | Related Articles | Metrics

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Recent Progress on Surface Modification and High Value-added Utilization of Kapok Fiber Xiaojie BAI,Xiuchun DENG,Zuyou ZHUO,Yandan CHEN 2020, 40 (2):  16-24.  doi: 10.3969/j.issn.0253-2417.2020.02.002 Abstract ( 848 )   HTML ( 822155279 )   PDF (3977KB) ( 742 )   Save The inherent properties of kapok fiber were summarized, such as light weight, high degree of hollowness up to 80%-90%, and super-hydrophobic surface, etc. Meanwhile, physical and chemical modification methods which could be widely used to improve the application characteristics of kapok fiber were introduced. The recent research progress focused on the application of kapok fiber and/or its modified treatment as eco-friendly oil-absorbing material, lithium-sulfur battery anode material and supercapacitor electrode material as well as the development of kapok fiber/polyester composite for sound absorbing material was presented. Based on the comprehensive research status of kapok fiber at home and abroad, the current challenges and future prospects on kapok fiber exploitation with respect to expanding new uses and high value-added utilization were highlighted. Figures and Tables | References | Related Articles | Metrics

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Application of Woody Activated Carbon in Refining of Rice Bran Oil Ao WANG,Kang SUN,Jianchun JIANG,Guanghua LIU 2020, 40 (2):  25-32.  doi: 10.3969/j.issn.0253-2417.2020.02.003 Abstract ( 550 )   HTML ( 7463 )   PDF (601KB) ( 678 )   Save Based on the analysis of the physicochemical properties of activated carbon, the refining effects of four activated carbon prepared by chemical method and two activated carbon prepared by physical methods on the grade four rice bran oil were studied. The influence of refining process conditions on the refining effect of the grade four rice bran oil was also investigated. Furthermore, the adsorped activated carbon was regenerated by solvent method, and the refining effect of regenerated activated carbon on the rice bran oil was analyzed, as well as the recovery of rice bran oil and oryzanol. The decolorization performance of caramel were the key factors affecting the decolorization effect of activated carbon on the refinement of grade four bran rice oil. The best technological conditions of CAC4 were as follows:adsorption temperature 50℃, adsorption time 30 min, one-time adding. Under these conditions, when the additive contents of activated carbon 30%, the color degree of refined rice bran oil was yellow 30 and red 3.0 (the width of color trough was 133.4 mm), which reached the first-grade rice bran oil standard. The content of oryzanol was 0.24%, the loss rate of oryzanol was 89.25%, and the loss rate of rice bran oil was 46.7%. When CAC4 was used to adsorbed pigment twice, the decolorization effect of rice oil was still obvious. The regeneration of activated carbon results showed that the adsorption performance of activated carbon was basically restored after regeneration, and it had good refining effect of rice bran oil. The color degree of rice oil refined byCAC4 after tertiary regeneration was yellow 30 and red 2.5. At the same time, the recovery of rice bran oil and oryzanol as well as the selective separation of pigment molecules could be realized during the regeneration process of activated carbon. Figures and Tables | References | Related Articles | Metrics

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Preparation of Xylooligosaccharides by Ethanol Precipitation Separation from Autohydrolysis of Enzymatic Hydrolysis Residuce of Xylan Zhina LIAN,Yan'e WANG,Jing LUO,Qiang YONG,Shiyuan YU 2020, 40 (2):  33-41.  doi: 10.3969/j.issn.0253-2417.2020.02.004 Abstract ( 860 )   HTML ( 730137601 )   PDF (690KB) ( 734 )   Save Enzymatic hydrolysis residue of xylan was autohydrolyzed, and the autohydrolysate was then fractionated by two-step ethanol precipitation. The obtained three kinds of xylan fractions with varied degree of polymerization (Dp) were evaluated through in vitro proliferation by Bifidobacterium adolescentis. The autohydrolysis was carried out at 180℃ for 40 min to obtain autohydrolysate mainly contained xylooligosaccharides (XOS) with Dp of 2-6. The content of XOS was 57.36% of the xylan in the autohydrolysate, and the yield of XOS was 26.54% of the xylan in the feedstock. Two-step ethanol precipitation could fractionate the xylan in the autohydrolysate into sample S1, S2 and S3, with the range of Dp of 24-122, 7-19 and 1-6, respectively. Low Dp of sample S3 contained mainly XOS which was 95.91% and exhibited significant prebiotic activity. After 36 h incubation, the cell concentration was 0.25 g/L, 4.72 times of the initial, with the sugar residue of 43.48%, and with the concentration of short-chain fatty acids of 1.96 g/L. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Characterization of Functional Ethyl Cellulose-rosin Hybrid Membrane Yuling QIU,Xiaoliang GUO,Chuanwei LU,Chunpeng WANG,Jifu WANG,Fuxiang CHU 2020, 40 (2):  42-48.  doi: 10.3969/j.issn.0253-2417.2020.02.005 Abstract ( 721 )   HTML ( 338231313 )   PDF (751KB) ( 726 )   Save A class of bio-based hybrid membranes named EC-g-MPA-ESO were prepared by the esterification reaction between the epoxidized soybean oil (ESO) and the ethyl cellulose-rosin-based polymer (EC-g-MPA), synthesized by grafting rosin derivative maleopimaric acid (MPA) onto the ethyl cellulose (EC) backbone via esterification reaction. The chemical structure of EC-g-MPA was characterized by FT-IR, 1H NMR, and UV-Vis spectrophotometer, by which have confirmed the successful preparation of EC-g-MPA. Then, TGA, DSC, UV-Vis spectrophotometer, and tensile test were applied to investigate the thermal stability, curing properties, UV absorption properties, and mechanical properties of bio-based hybrid membrane EC-g-MPA-ESO with different ESO content. The results showed that the bio-based hybrid membrane exhibited UV absorption property. Compared with EC and EC-g-MPA, EC-g-MPA-ESO exhibited low glass transition temperature and excellent toughness. Mechanical test showed that when ESO content was 20% (based on the mass of EC-g-MPA), the blend film shows the best mechanical properties, and tensile strength reaches the maximum value of 12.07 MPa. Cyclic tensile test confirmed that the elastic restitution coefficient of EC-g-MPA-ESO increased with the increase of elongation. As the elongation reached 80%, the elastic restitution coefficient reached 54.6%, indicating that EC-g-MPA-ESO had good elastomer behavior and could be used as a thermoplastic elastomer. The hybrid membrane consists of cellulose matrix and rosin functional groups, and could find potential application in UV absorption and degradable plastic film. Figures and Tables | References | Related Articles | Metrics

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Effects of Growth Conditions on Content, Components and Antimicrobial Activity of Volatile Oil of Cinnamon Leaves Zuohui ZHANG,Yongqing TONG,Guangzhi HUANG,Liangwu BI 2020, 40 (2):  49-54.  doi: 10.3969/j.issn.0253-2417.2020.02.006 Abstract ( 541 )   HTML ( 7 )   PDF (1434KB) ( 571 )   Save Essential oils of cinnamon leaves from different growth conditions were extracted by steam distillation method, respectively. The chemical constituents were analyzed by gas chromatography-mass spectrometry, and the relative content of each constituent was determined by area normalization. Their antimicrobial activities on three common pathogens were tested by filter paper method. The results indicated that the essential oil yield of cinnamon leaves were affected by tree age, planting density and slope aspect. Among them, tree age had the greatest impact. The highest yield of essential oil was obtained from 15-year-old sparse planting cinnamon leaves (No.3, 1.60%), the lowest was obtained from 20-year-old (No.7, 0.51%). The second was slope aspect, yield of essential oil obtained from 15-year-old south slope cinnamon leaves (No.5, 1.20%) was much higher than that obtained from 15-year-old north slope cinnamon leaves (No.6, 0.55%). The minimal impact was caused by planting density, yield of essential oil obtained form 15-year-old sparse planting cinnamon leaves (No.3, 1.60%) was higher than that obtained from 15-year-old close planting cinnamon leaves (No.4, 1.34%). The components and their GC contents of essential oil of cinnamon leaves from different growth conditions were different. A total of 28 chemical constituents were identified in the seven samples, among them, 15-year-old sparse planting (No.3) had the most kinds of essential oil components (21 kinds), 15-year-old dense plants (No.4) and 15-year-old south slope (No.5) contain the least kinds (both of 7 kinds). Trans-cinnamaldehyde was the most abundant component in the samples, of which the highest GC content was in No.4 (90.26%), and the lowest GC content was in 10-year-old (No.2, 67.73%). The common components were benzaldehyde, benzenepropanal, cis-cinnamaldehyde and trans-cinnamaldehyde. The order of inhibition effect on three experimental bacteria was Staphylococcus aureus > Escherichia coli > Pseudoinonal aeruginosa at the mass concentrations of 500 g/L. The diameters ranges of bacteriostasis circles were 22.57-39.63 mm, 27.58-34.31 mm and 16.39-23.89 mm, respectively. Among them, 20-year-old (No.7) had the strongest inhibition on S. aureus(39.63 mm), 15-year-old close planting (No.4) had the strongest inhibition on E. coli(34.31 mm) and 5-year-old (No.1) had the strongest inhibition on P. aeruginosa(23.89 mm). Figures and Tables | References | Related Articles | Metrics

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Improvement of Properties of Fast-growing Poplar by Modified Rosin Ji XU,Zhaolan ZHAI,Xinyan YAN,Zhanqian SONG,Shibin SHANG,Xiaoping RAO 2020, 40 (2):  55-62.  doi: 10.3969/j.issn.0253-2417.2020.02.007 Abstract ( 593 )   HTML ( 33 )   PDF (5577KB) ( 690 )   Save The tricyclic diterpene structure of rosin has unique properties. The fast-growing poplar was modified by using the refined rosin(RR), polymerized rosin(PR) and acrylic acid rosin(AAR) as madifier and ethanol as solvent to prepare the impregnating solution with the mass fraction of 20%. The fast-growing poplar was modified by impregnation method to obtain refined rosin modified wood (RRMW), polymerized rosin modified wood (PRMW), acrylic acid rosin modified wood (AARMW), and impregnated with absolute ethanol to obtain control wood (CW). The structure of the modified materials was characterized by infrared spectroscopy (FT-IR), scanning electron microscope (SEM), confocal laser scanning microscope (CLSM) and X-ray diffraction (XRD). The water resistance and mechanical properties of the modified materials were tested. The results showed that the C[FY=, 1]O absorption peak of the FT-IR for the modified material was significantly enhanced at 1691 cm-1. XRD analysis showed that the crystal plane diffraction peak had no obvious change. It was clearly observed in the SEM and CLSM images that the rosin was deposited in the wood cell lumen and infiltrated into the wood cell wall, which indicated that the modified rosin entered the wood cells, but had no effect on the structure of wood cellulose. The results of performance test showed that the properties of the three kinds of modified wood were improved, and the improvement of acrylic acid rosin modified wood was the most significant. The water resistance of AARMW was significantly enhanced, and the water uptake rate was 79.68%, while that of the control wood was 186.28% after 12 days of impregnation. The contact angle of AARMW was 88.78° in 180s, which was only 12% lower than 100.09° in 15s. However, the contract angle of control wood decreased from 44.34° at 15s to 0° at 180 s. In addition, compared with the control wood, the modulus of rupture (MOR), modulus of elasticity (MOE), and compression strength (CS) of AARMW increased by 18.09%, 27.51% and 17.85% respectively, which showed that the mechanical properties of fast-growing poplar were obviously improved. Figures and Tables | References | Related Articles | Metrics

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Performance Evaluation of Chemi-mechanical Pulping Obtained from Five Kinds of Common Fast-growing Pulpwood in Hainan Province Hua ZHU,Ting WU,Guigan FANG,Long LIANG,Beiping ZHU,Guanghui SHE 2020, 40 (2):  63-68.  doi: 10.3969/j.issn.0253-2417.2020.02.008 Abstract ( 619 )   HTML ( 17 )   PDF (595KB) ( 670 )   Save Five species of fast-growing pulpwood (Eucalyptus urophylla×E. grandis, Eucalyptus urophylla, Eucalyptus urophylla×E. tereticornis, Acacia mangium, Acacia crassicarpa) in Hainan Province were collected and converted into pulping. Then, their pulping performance were evaluated by using P-RC APMP as the process. The experimental results showed that the pulp yield of E. urophlla×E. tereticornis was the highest, reaching 91.2%, whereas the yield of A. crassicarpa pulp was the lowest, reaching 84.2% under the same pulping process conditions. When the pulp was milled to the same Canadian Standard Freeness of 300 mL, the electricity consumption of A. mangium pulp was the lowest, 1 209 kW·h/t, while that of the E. urophylla×E. grandis was the highest, 1 361 kW·h/t. The E. urophylla×E. grandis pulp had the highest bulk of 2.84 cm3/g. The bulk of A. mangium pulp and E. urophlla×E. tereticornis pulp were lower at 2.45 and 2.51 cm3/g, respectively. The strength performance of A. mangium pulp was the best, and its tensile strength, burst strength and tear strength were 28.42 N·m/g, 1.54 kPa·m2/g, and 2.7 mN·m2/g, respectively. The strength properties of the E. urophylla×E. grandis pulp was the worst. The whiteness of E. urophlla×E. tereticornis pulp and E. urophylla pulp were the highest (about 83% (ISO)), and the whiteness of A. mangium pulp was the lowest (about 78% (ISO)). Figures and Tables | References | Related Articles | Metrics

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Preparation of Acrylic Pimaric-sucrose Ester by Solvent-free Process and Its Adsorption Properties at Air-water Interface Juying ZHOU,Mengjun ZOU,Huazhen LIAO,Yanzhi ZHAO,Haitang XU,Liqun SHEN 2020, 40 (2):  69-75.  doi: 10.3969/j.issn.0253-2417.2020.02.009 Abstract ( 524 )   HTML ( 5 )   PDF (770KB) ( 540 )   Save Acrylic pimaric-sucrose ester was synthesized from acrylamicarboxylic acid and sucrose by esterification at high temperature under solvent-free conditions, which structure was characterized by IR, NMR and gel permeation chromatography and critical micelle concentration (CMC) was measured. The reorientation theory was used to analyze the adsorption behaviors of acrylic pimaric-sucrose ester surfactant at the air-water interface, including morphological change and adsorption capacity. The results showed that the acrylic pimaric-sucrose ester was successfully synthesized by the method, and the CMC value the synthesized ester was 2.2 g/L. With the increase of surfactant concentration, the solvent molar fraction at the air-water interface decreased, while the molar fraction of acrylic pimaric-sucrose ester increased. The adsorption of acrylic pimaric-sucrose ester at the air-water interface was divided into state 1 and state 2, and the adsorption capacity on the interface was calculated respectively, which was up to 1.9 mmol/m2 in state 2. As the surface pressure increased, the number of molecules in state 1 increased first and then decreased, while the number of molecules in state 2 dominated and continued to increase. The molar free energies (ΔG) of adsorption and micelles of acrylic pimaric-sucrose ester were -20.67 kJ/mol and -15.16 kJ/mol, respectively, indicating that acrylic pimaric-sucrose ester was preferentially adsorbed on the interface and formed micelles after reaching saturation. Figures and Tables | References | Related Articles | Metrics

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Effect of Different Extraction Agents on Enrichment of ActiveComponents from Wood Vinegar Xincheng LU,Jianchun JIANG,Jing HE,Kang SUN,Yunjuan SUN 2020, 40 (2):  76-82.  doi: 10.3969/j.issn.0253-2417.2020.02.010 Abstract ( 538 )   HTML ( 101 )   PDF (485KB) ( 478 )   Save The enrichment effect of different extraction agents on active components of wood vinegar from waste fir plate was studied. The results showed that different extraction agents exhibited different effects on the enrichment of active components in wood vinegar. Ethyl acetate, chloroform and ether exhibited good enrichment effect on phenolic substances, which ether present better extraction performance; ethyl acetate and chloroform had good enrichment effect on ketones; 3 extractants had no obviously enrichment effect on esters, aldehydes and alcohols, and they were not conducive to the enrichment of acid substances. Methanol addition was contributed to increase the enrichment effect of ether on phenolic substances. When the volume ratio of ether to methanol was 2:1, GC content of phenolic compounds reached to 66%, which was 1.96 times that of un-treated wood vinegar. Figures and Tables | References | Related Articles | Metrics

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Preparation, Characterization of Pt-Re-MCM-41 Catalyst and Its Catalytic Conversion of Corncob for Producting Furan Compounds Wenbin LI,Yunwu ZHENG,Shuirong LI,Yi LU,Zhifeng ZHENG 2020, 40 (2):  83-92.  doi: 10.3969/j.issn.0253-2417.2020.02.011 Abstract ( 545 )   HTML ( 118 )   PDF (1304KB) ( 652 )   Save A series of Pt-Re-MCM-41 catalysts with different metal loading were prepared by step impregnation method with MCM-41 as support. The physical and chemical properties of the catalysts were characterized by nitrogen adsorption-desorption, X-ray diffraction (XRD) and NH3 temperature programmed desorption (NH3-TPD). The effect of Pt-Re-MCM-41 on the catalytic conversion of corncob pyrolysis products to furan compounds, including its repeated using and regeneration performance, were discussed. The experimental results showed that Pt and Re were uniformly dispersed on the catalyst surface, and the structure and properties of MCM-41 were not changed after loading, but the surface area, pore volume of the catalyst decreased and the average pore diameter increased after loading. The catalyst system had weak acid and medium strong acid at the same time. After Pt and Re loading, the content of the two acid sites on the catalyst surface increased. The type and number of compounds detected by GC×GC were, about 4-5 times than that detected by GC. The addition of the catalyst inhibited the production of alcohols, acids, nitrogen and sugars, and promoted the formation of ketones, furan and hydrocarbons, but had little effect on esters and phenols. The Pt-Re-MCM-41 catalyst could increase the GC content of furan compounds. The GC content could reach 33.12% with 1.0%Pt-1.0%Re-MCM-41 as catalyst and the catalytic temperature was 450℃ and increased by 12.11 percentage point compared with that without catalyst. Low catalytic temperature (≤ 450℃) was favorable for the formation of 2 (5H) -furanone and 2-furan methanol, and high catalytic temperature (≥ 500℃) was beneficial for furfural, 2-methylfuran and 3-furfural formation. The activity of the 1.0%Pt-1.0%Re-MCM-41 catalyst was reduced after three times, and the activity was basically recovered after calcination. Among them, the furan compound GC antent reached 32.6%. Figures and Tables | References | Related Articles | Metrics

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Preparation and Properties of Hydrophobic Wood Flour-silica Aerogel Composites Weishan SONG,Shirui LIU,Xue ZHAO,Yao CHEN,Jianmin GAO 2020, 40 (2):  93-98.  doi: 10.3969/j.issn.0253-2417.2020.02.012 Abstract ( 439 )   HTML ( 4 )   PDF (3368KB) ( 619 )   Save Hydrophobic wood flour-silica aerogel composites were prepared by sol-gel method and ambient pressure drying with tetraethyl orthosilicate (TEOS) and methyltrimethoxysilane (MTMS) as co-precursors. The effects of different particle sizes (0.42-0.84 mm, 0.25-0.42 mm, 0.18-0.25 mm) of balsa woodflour on the properties of wood flour-silica aerogel composites were studied. Through the analysis of thermal conductivity, contact angle, infrared spectrum, thermogravimetric and compressive strength of composite materials, it was observed that the density, thermal conductivity, compressive strength and contact angle of the composites decreased with the increase of particle size of the wood flour. Wood flour with the particle size of 0.25-0.42 mm could endow aerogel composite with better material properties. Namely, the composite density was 0.168 g/cm3, the thermal conductivity was 0.033 7 W/(m·K), the compressive strength was 0.15 MPa, and the contact angle was 155.72°. The prepared composite material has the characteristics of excellent heat preservation performance, light weight and high hydrophobicity. Figures and Tables | References | Related Articles | Metrics

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Chemical Constituents from Leaves of Cyclobalanopsis fleuryi Tiange DAI,Yafeng WANG,Ruijie HE,Dianpeng LI,Yonglin HUANG 2020, 40 (2):  99-103.  doi: 10.3969/j.issn.0253-2417.2020.02.013 Abstract ( 789 )   HTML ( 20495 )   PDF (530KB) ( 769 )   Save The ethanol extract of the leaves of Castanopsis fleuryi was isolated by Sephadex LH-20, MCI gel CHP 20P, Toyopearl HW-40F, Chromatorex C18 column chromatography and simi-preparative HPLC purification techniques to obtain ten compounds. Their structures were elucidated by spectroscopic data and comparison with literatures as:gallic acid(1), ethyl gallate(2), dehydrodigallic acid(3), gentisic acid 5-O-β-D-glucoside(4), cretanin(5), apigenin(6), kaempferol-7-O-β-D-glucoside(7), astilbin(8), aromadendrin7-O-β-glucopyranoside(9), amarusine A(10). All compounds were isolated from this plant for the first time. Figures and Tables | References | Related Articles | Metrics

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Effects of Poplar Wood Fiber (PWF) Size on Mechanical Properties of PWF/Epoxy Resin Composites Hongliang MA,Jian CHEN,Jian JIAO,Yongjun DENG,Zhenwu KONG,Guigan FANG 2020, 40 (2):  104-108.  doi: 10.3969/j.issn.0253-2417.2020.02.014 Abstract ( 564 )   HTML ( 3 )   PDF (6536KB) ( 688 )   Save Poplar wood fiber (PWF) with different sizes was prepared from poplar residues of chemi-mechanical pulping and subsequent treatments (directly drying and solvent replacement). The PWF/epoxy resin (PWF/E51) composites were prepared by hot pressing molding method. The effects of fiber size on the mechanical properties of composites were investigated by the analysis of micro-morphology and size of the PWF as well as the micro-morphology of the impact fracture surface of the composites. The results showed that the fiber size had a significant effect on the mechanical properties of composites. With the increase of the ratio of length to diameter of PWF, the impact and flexural strength of PWF/epoxy resin composites were increased first and then decreased. Among them, the PWF with the ratio of length to diameter 14.8, which were prepared from the solvent replacement, showed the best reinforcement of the mechanical strength of the epoxy resin composites. And the impact strength and flexural strength were 7.1 kJ/m2 and 68.2 MPa, respectively. In addition, the mechanical strength of composites reinforced with the solvent replacement PWF was higher than that reinforced with the directly dried PWF. Figures and Tables | References | Related Articles | Metrics

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Extraction, Purification and Antioxidant Activity of Cinnamon Distillation Residues Xian CHENG,Liangwu BI,Weixing ZENG,Zhendong ZHAO,Yuxiang CHEN,Zuohui ZHANG 2020, 40 (2):  109-116.  doi: 10.3969/j.issn.0253-2417.2020.02.015 Abstract ( 578 )   HTML ( 50351104 )   PDF (679KB) ( 984 )   Save The bioactive compounds were extracted from cinnamon distillation residue(CR) by using ultrasonic-assisted extraction technology, and the extract were further purificated with AB-8 macro porous resin. The contents of total flavonoid and polyphenol were measured by UV spectrophotometer, and the contents of six main components were detected by HPLC. The antioxidant properties of the extract were evaluated. The results showed that the contents of flavonoid and polyphenol in the sample were increased by about 2.6-4.2 times after elution with 80% ethanol. The contents of flavonoid extracted from the residues of leaves (LR), twigs (TR) and barks (BR) were 18.50%, 53.93% and 44.48%, and the contents of polyphenol were 2.60%, 37.56% and 28.16%, respectively. The components with the maximum content in LR, TR and BR extracts were coumarin or cinnamic acid. The contents of the six main components in the extracts of LR, TR and BR were significantly different and decreased in the following order TR > BR > LR. The total antioxidant capacities of TR and BR extracts were 8.12 and 7.5 U/mL. The IC50 value of the scavenging effects on DPPH·of TR, BR and LR extracts were 0.017, 0.021 and 0.150 g/L, respectively. The IC50 of the scavenging effects on·OH of TR extracts was 0.12 g/L. TR and BR have good total antioxidant capacity and the scavenging effects on DPPH· and·OH. LR extracts have relatively weak antioxidant capacity. Figures and Tables | References | Related Articles | Metrics

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Catalytic Pyrolysis of Biomass to Produce Specific High Value-added Furans and Aldehydes Chemicals Bozheng LI,Dongmei BI,Yongjun LI,Mei JIANG 2020, 40 (2):  117-124.  doi: 10.3969/j.issn.0253-2417.2020.02.016 Abstract ( 643 )   HTML ( 8258 )   PDF (1139KB) ( 782 )   Save Using rape straw, corn straw and camphor wood powder as raw materials, ZnCl2 was selected as a catalyst to carry out catalytic pyrolysis experiments in a horizontal tubular furnace reactor. The yields of the high value-added chemicals, e.g. furfural (FF), paraformaldehyde and 5-methylfurfural, in the bio-oil were taken as evaluation indexes. The results showed that the bio-oil yield of camphor wood powder was the highest, up to 51.76%, without catalyst. When ZnCl2 was the catalyst with a mass ratio of 1:1 in the pyrolysis, the bio-oil yield of the three raw materials decreased. And the bio-oil yield of camphor wood powder (30.50%) decreased significantly. The yield of aldehydes in the bio-oil obtained from corn straw and camphor wood powder increased to 0.48% and 0.84%, respectively. After catalytic pyrolysis of rape straw, corn straw and camphor wood powder, the yield of furans in the bio-oil increased by 253.72%, 85.05%, and 202.32%, respectively. The yield of FF in bio-oil increased by 470.41%, 313.87%, and 340.99%, respectively. The yield of 5-methylfurfural increased by 318.18%, 200.00%, and 213.04%, respectively. Meanwhile, the yield of paraformaldehyde in the bio-oil obtained from the catalytic pyrolysis of corn straw by ZnCl2 increased increased slightly. Figures and Tables | References | Related Articles | Metrics

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The Optimization of Synthesis Process of Nopinone Yunfei SHI,Hui ZHANG,Xuyang ZHONG,Xinying DUAN,Shulan CHEN,Shengliang LIAO 2020, 40 (2):  125-130.  doi: 10.3969/j.issn.0253-2417.2020.02.017 Abstract ( 734 )   HTML ( 4123 )   PDF (469KB) ( 634 )   Save Nopinone is an important forest derivative derived from the oxidation reaction of β-pinene, which is of great significance for further deep processing and utilization of naloxone.In this paper, the optimization for the synthesis process of nopinone from β-pinene was studied.The effects of reaction time, reaction temperature, type and amount of catalyst, n(potassium permanganate):n(β-pinene), type of oxidant, solvent type on reaction conversion and selectivity were discussed.The results showed that when the reaction time was 3 h, the reaction temperature was 21-24℃, the catalyst was cetyltrimethylammonium bromide (CTAB), the amount of catalyst was 0.20 g, the molar ratio of potassium permanganate to β-pinene was 3.2:1, using potassium permanganate as oxidant, acetone as solvent, the conversion rate of the synthesis reaction of nopinone is 99.5%, and the selectivity is 92.2%. Figures and Tables | References | Related Articles | Metrics