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30 March 2021, Volume 55 Issue 2 Previous Issue   
Research Report
Preparation and Characterization of Poly(D-lactic Acid-co-Glucose) Copolymer by Hydroxyl Protection Method
Qianjin ZHU, Liyan QI, Dan CAO, Tingting LIU, Qinwei GAO
2021, 55 (2):  1-8.  doi: 10.3969/j.issn.1673-5854.2021.02.001
Abstract ( 60 )   HTML ( 7 )   PDF (705KB) ( 53 )  

1, 2:5,6-Di-O-isopropylidene-α-D-glucofuranose(ODG) was prepared with α-D-glucose as raw material by hydroxyl protection method. Then poly(D-lactic acid) (PDLA) coplymerized with ODG to obtain PDLAODG.Poly(D-lactic acid-co-glucose) copolymer (PDLAG) was obtainedby removing the hydroxyl protective groups of glucofuranose in PDLAODG.The structure and properties of PDLAODG and PDLAG were measured by 1H NMR spectroscopy, Fourier transform infrared spectroscopy, thermogravimetry, differential scanning calorimetry, X-ray diffraction, contact angle and water absorptionetc. The results showed that PDLAODG and PDLAG could be prepared by hydroxyl protection methodand melt coplymerization. The number of PDLA chains linking to glucose groups could be regulated by the ratio of ODG to PDLA. when the molar ratio of ODG to PDLA ≥ 5, the copolymer only contained one D-lactic acid chain. The PDLAchains of both PDLAODG and PDLAG could form α-type crystals. With the increase of glucose group content, the melting point of PDLAODG decreased from 151.5 ℃ to 147.9 ℃, the crystallinity decreased from 58.2% to 42.1%, the water contact angle decreased from 78.1° to 71.5°, the melting point of PDLAG decreased from 156.8 ℃ to 149.4 ℃, and the crystallinity decreased from 61.9% to 50.0%, the water contact angle from 70.1° to 64.4°. The hydrophilicities of PDLAODG and PDLAG were improved compared with that of neat PDLA, while the crystallinity, melting point and hydrophilicity of PDLAG were all higher than those of PDLAODG with the same glucose group content, i.e.the thermal stability, crystallization performance and hydrophilicity of PDLAG were all improved.

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Analysis of Gasification Process and Gasification Characteristics of Downdraft Fixed Bed Gasifier
Xiangwen CHENG, Lizhi LIU, Rong WEI
2021, 55 (2):  9-15.  doi: 10.3969/j.issn.1673-5854.2021.02.002
Abstract ( 45 )   HTML ( 3 )   PDF (5402KB) ( 35 )  

In order to study the effect of the multiphase reaction flow field on the gasification process in downdraft fixed-bed gasifier, based on Fluent software, Euler Langrange model was established to track the movement of straw particles. P1 model was used to simulate the radiation heat transfer process of gasification process. At the same time, the gasification characteristics of straw downdraft gasifier were analyzed by coupling chemical reactions.The results showed that when the fuel coefficient was 0.26 and the particle size of straw was 13 mm, the volatiles of straw begin to react with the gastifier at the distance of 4.85 m from the bottom outlet of the burner. The flame temperature at the center of the gasifier increased, and then decreased with the depletion of volatiles. When the particle size of straw particles increased from 10 mm to 30 mm, the flammable gas content gradually decreased, but the content gap was not large.When the particle size of straw reached 40 mm, the temperature in gasifier dropped rapidly, then the serious phenomenon of incomplete dry volatilization would happen.

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Structural Properties of Niobium Oxide/Woody Activated Carbon Fiber Composites
Xin LIU, Xiaojun MA
2021, 55 (2):  16-22.  doi: 10.3969/j.issn.1673-5854.2021.02.003
Abstract ( 34 )   HTML ( 3 )   PDF (2764KB) ( 31 )  

Niobium oxide/wood activated carbon fiber (Nb2O5/ACHF) at different calcination temperatures(400, 600 and 800 ℃) was prepared by impregnating niobium oxalate and changing calcination temperature with wood activated carbon fiber as support. The structure, surface pore size and so on of the as-prepared niobium oxide/wood activated carbon fiber were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray electron spectroscopy (XPS) and fully automatic surface area and pore size analysis (BET), and the electrochemical performance was preliminarily analyzed. The results showed that as the calcination temperature increased, the crystal form of the orthogonal niobium oxide crystal on the surface of the fiber became better, and the particle diameter became larger. The C-C bond content of the surface functional group decreased gradually, and the C-O bond increased, The specific surface area decreased from 1 476.65 m2/g(400 ℃) to 1 302.31 m2/g(800 ℃). The micropore rate decreased by 10.79 percent. In addition, the prepared niobium oxide/wood activated carbon fiber had excellent double layer capacitance and pseudocapacitance properties. The Nb2O5/ACHF-800 surface of 800 ℃ calcined sample had multistage pore structure. In favor of its electrochemical performance, the specific capacitance was up to 155 F/g in KOH electrolyte with the current density of 1 A/g.

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Quaternization of Sugar Beet Pulp and Its Adsorption Property to Nuclear Fast Red
Yanxia ZHANG, Xue YU, Yang LI, Siming ZHU
2021, 55 (2):  23-30.  doi: 10.3969/j.issn.1673-5854.2021.02.004
Abstract ( 38 )   HTML ( 3 )   PDF (1067KB) ( 28 )  

In order to improve the adsorption performance of sugar beet pulp as a biosorbent, sugar beet pulp(SBP) was modified with quaternary ammonium salt tetrabutylammonium bromide(TBAB) to obtain the modified adsorbent TBAB-SBP. The adsorption performance of TBAB-SBP on nuclear fast red was explored. Its kinetics and thermodynamics were analyzed, and the chemical structure and surface morphology of TBAB-SBP were characterized by using FT-IR, XRD and SEM. The results showed that TBAB could be effectively loaded on the surface of SBP, and the types and number of functional groups increased. The static adsorption process conditions for nuclear fast red on TBAB-SBP in wastewater were pH value of the solution 2.0, 100 mL of nuclear fast red solution with mass concentration of 100 mg/L, amount of adsorbent 0.6 g, treatment time 180 min, adsorption temperature 25 ℃. Under these conditions, the pigment removal rate of TBAB-SBP was 94.44%, which was about 12% higher than that of SBP; the adsorption equilibrium data conformed to the Langmuir isotherm model; the adsorption process was a spontaneous exothermic process; the TBAB-SBP adsorption nuclear fast red process conformed to the qseudo-second-order equation.

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Effect of Chemical and Biological Compound Tapping Irritant Agent on Resin-increasing and Physical Indexes of Pinus yunnanensis
Ruiling WANG, Xiangyi LIU, Jianxiang LIU, Chunhua WU
2021, 55 (2):  31-37.  doi: 10.3969/j.issn.1673-5854.2021.02.005
Abstract ( 33 )   HTML ( 3 )   PDF (503KB) ( 25 )  

The chemical tapping irritant agent with rare earth as the main component and two biological tapping irritant agents including Ethephon and α-naphthylacetic acid were applied in the experiment of increasing resin of Pinus yunnanensis. The effects of increasing resin were good, and the average increasing resin rates were 31.48% and 20.20%, respectively. The mass fraction of turpentine in resin increased by 24.6%, and the quality of resin improved. The physiological indexes of Pinus yunnanensis treated with tapping irritant agent were tested. The results showed that the maximum value of fresh weight and dry weight increased by 34.57% and 37.89%, respectively. The contents of chlorophyll, soluble sugar and soluble protein also increased, the maximum improvement rates were 59.94%, 25.88% and 42.85%, respectively. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) of Pinus yunnanensis increased with the maximum increments of 178.38%, 137.60% and 43.22%. These enzymes could help to improve cold tolerance and environmental adaptability of plants, reduce the content of malondialdehyde (MDA), with the maximum decrease rate of 36.91% to ensure the stability of plant cells, and promote resin increasing.

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Effect of Process Parameters on Formaldehyde and TVOC Content in Plywood Bonded with Bio-oil Phenol Formaldehyde Resins
Ping HUANG, Fan YANG, Liangliang JIA, Jian LI, Dongbing LI
2021, 55 (2):  38-44.  doi: 10.3969/j.issn.1673-5854.2021.02.006
Abstract ( 42 )   HTML ( 3 )   PDF (500KB) ( 42 )  

To explore the effects of 6 factors (bio-oil replacement ratio, molar ratio of formaldehyde and phenol (nF/nP), hot press temperature, pressure and time, and amount of adhesives) of the resin preparation and hot press processes on the content of formaldehyde and total volatile organic compounds (TVOC) in the bio-oil phenol formaldehyde plywood (BPFP) panels, an L25 (56) orthogonal experiment design was executed. Head space solid-phase micro-extractions (HS-SPME) combined with gas chromatography/mass spectrometry (GC/MS) was employed to detect the content of free formaldehyde and TVOC in the BPFP panels. The results showed that under the conditions of the bio-oil replacement ratio of 60%, nF/nP of 1.6, hot press temperature of 190 ℃, hot press duration of 4 min, hot press pressure of 1.2 MPa, and amount of adhesives applied of 200 g/cm2, formaldehyde emissions was the lowest. Hot press temperature and pressure had a significant effect on the formaldehyde content, whereas the replacement ratio of fast pyrolysis bio-oil to phenol and the amount of wood adhesives applied had a minor effect. Under the conditions of bio-oil replacement ratio of 60%, nF/nP of 2.2, hot press temperature of 190 ℃, hot press duration of 5.5 min, hot press pressure of 1.4 MPa, and amount of adhesives applied of 210 g/cm2, the content of TVOC in the plywood was the lowest.

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Synthesis and Antifungal Activity of Hydronopyl Gemini Quaternary Ammonium Salts
Xuezhen FENG, Zhuanquan XIAO, Guorong FAN, Zongde WANG
2021, 55 (2):  45-49.  doi: 10.3969/j.issn.1673-5854.2021.02.007
Abstract ( 30 )   HTML ( 3 )   PDF (522KB) ( 25 )  

Three novel hydronopylgemini quaternary ammonium salts, namely tetramethylene-1,4-bis-(hydronopyl dimethyl ammonium chloride)(2a), pentamethylene-1,5-bis-(hydronopyl dimethyl ammonium chloride)(2b) and hexamethylene-1,6-bis-(hydronopyl dimethyl ammonium chloride)(2c) were synthesized from hydronopyl dimethyl amine and three α, ω-dibromoalkanes, respectively. Their structures were characterized by NMR and MS. The inhibition activities of the target compounds against nine plant pathogens were evaluated by mycelium growth rate method. The results showed that the three compounds had excellent antifungal activity against the tested plant pathogens, and compound 2c had the best inhibitory effect, in which its inhibitory rates on Colletotrichum acutatu, Sphaeropsis sapinea, Fusicoccum aesuli, Phytophthora parasitica var.Nicotianae and Fusarium oxysporum were much higher than that of chlorothalonil at all concentrations(12.5-200 mg/L) tested.

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Preparation and Flame Retardant Properties of Dimethyl Methylphosphonate/Sodium Lignosulfonate Polyurethane Foam
Ze YU, Xu LI, Jianan WANG, Zhiming LIU
2021, 55 (2):  50-54.  doi: 10.3969/j.issn.1673-5854.2021.02.008
Abstract ( 32 )   HTML ( 3 )   PDF (1285KB) ( 25 )  

Sodium lignosulfonate (SLS) was used to replace part of polyether polyol, and dimethyl methylphosphonate (DMMP) was used as additive flame retardant, then the sodium lignosulfonate polyurethane foam (SLS/PUF) was prepared by one-step foaming method.The flame retardant properties of the materials were analyzed by limiting oxygen index (LOI) test, and the influence of SLS substitution amount and DMMP addition amount on the material properties were explored. The burning behavior was studied by using the cone calorimeter (CONE). The test results showed that the flame-retardant SLS/PUF material had the best flame-retardant performance when the SLS substitution rate was 80%, and the LOI value reached 24.5%. On the basis of this replacement rate, when the addition amount of DMMP was 30%, the LOI value of the flame-retardant PUF material reaches 27.3%. Compared with pure PUF materials, the addition of SLS and DMMP reduced the heat release rate from 245.2 kW/m2 to 166.8 kW/m2, and the total heat release and total smoke release also reduced by 0.2 MJ/m2 and 0.4 m2 and reached 12.1 MJ/m2 and 3.4 m2. At the same time, the residual carbon content of the flame retardant added material was increased from 20.3% to 37.3%, which promoted the carbon formation of the material and made the SLS/PUF material have good flame retardant properties.

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Synthesis and Herbicidal Activity of Hydroxycitronellal Oxime and Its Alkyl Ethers
Yun PENG, Zhuanquan XIAO, Shengliang LIAO, Guorong FAN, Shangxing CHEN, Zongde WANG
2021, 55 (2):  55-59.  doi: 10.3969/j.issn.1673-5854.2021.02.009
Abstract ( 36 )   HTML ( 3 )   PDF (434KB) ( 29 )  

Hydroxycitronellal oxime(2) was synthesized from hydroxycitronellal(1) and hydroxylammonium chloride, and then reacted with bromoalkanes to give 4 hydroxycitronellal oxime alkyl ethers(3a-3d). The structures of the products were characterized by GC-MS, IR and NMR.The inhibitory effect of oxime and its alkyl ethers on the growth of annual ryegrass in different concentrations were determined by the plate method. The results showed that when the concentration of 3b was 0.31 mmol/L, the concentration of 3c was 0.63 mmol/L and the concentration of 3d was 2.50 mmol/L, the growth inhibition rate of the annual ryegrass roots were higher than that of diuronat the concentration of 10 mmol/L(94.1%). When the concentration of 3b and 3d were 0.31 mmol/L and the concentration of 3c was 0.63 mmol/L, the inhibitory rate on the growth of annual ryegrass stemswere higher than that of diuron at the concentration of 10 mmol/L(88.10%).

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Review Comment
Research Progress of Functionalized Wood in the Field of Polluted Water Purification
Ming ZHANG, Xiling DU, Junyou SHI, Yaoxing SUN, Jian LI, Chengyu WANG
2021, 55 (2):  60-70.  doi: 10.3969/j.issn.1673-5854.2021.02.010
Abstract ( 72 )   HTML ( 5 )   PDF (11985KB) ( 399 )  

Wood has unique advantages on industrial wastewater treatment including green, renewable, easy obtained, wide application, etc. This review gave an outline of the novel and functionalized wood-based composite (including wood filters, wood aerogel adsorption materials, wood sponge, etc.) prepared by depriving lignin and hemicellulose from the raw wood, loading functional nanomaterials and modifying functional groups on the raw wood for purifying the industrial wastewater containing heavy metal ions, microorganisms, organic dyes and oil stains. Then the influences of preparation technologies and modification methods on the types of pollutants, degradation efficiency, adsorption capacity, sterilizing effect, and recycling usability of wood for filtering and adsorbing the wastewater have been analyzed, and the potential problems and future application prospects of wood-based composite material in the field of water pollution purification were pointed out as well.

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