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    28 April 2022, Volume 42 Issue 2 Previous Issue    Next Issue
    Synthesis of Allyl Modified Lacquer and Its Characteristics of UV/Oxygen Curing
    Jian CHEN, Guomin WU, Shuping HUO, Zhenwu KONG
    2022, 42 (2):  1-9.  doi: 10.3969/j.issn.0253-2417.2022.02.001
    Abstract ( 185 )   HTML ( 1114603520 )   PDF (2766KB) ( 259 )   Save

    The allyl ether modified lacquer(AGE-L) was successfully prepared by the reaction of lacquer with allyl glycidyl ether(AGE), and subsequently reacted with methacrylic anhydride(MAA) to form a novel lacquer-based monomer with ether bond and ester bond(MAA-AGE-L). Their structures were then characterized by FT-IR, 1H NMR and 13C NMR, and their physical and chemical properties were tested. Additionally, the UV and oxygen(air) curing processes of raw lacquer, AGE-L and MAA-AGE-L were investigated, and the mechanical properties as well as the resistances to chemical media of the cured films were also studied. The results confirmed the successful synthesis of AGE-L and MAA-AGE-L, which were all brownish red liquids. The hydroxyl value of AGE-L was 193 mg/g, the iodine value was 1.89 g/g and the viscosity was 400 mPa·s. The hydroxyl value of MAA-AGE-L was 20 mg/g, the iodine value was 1.39 g/g and the viscosity was 2 000 mPa·s. Compared with lacquer, the surface drying time of MAA-AGE-L was shortened from 2 h to 50 min in presence of the oxygen(air) environment at 30 ℃ with the relative humidity of 80%, and the UV curing surface drying time was shortened from 50 s to 10 s. The pencil hardness of the cured film was H when AGE-L was irradiated by ultraviolet light for 120 s, whereas the pencil hardness of the paint film cured under oxygen(air) for one week was 2H. Moreover, they exhibited good adhesion, flexibility and impact strength. Allyl-modified lacquer films obtained by two curing methods had good water resistance, ethanol resistance, salt water resistance and acid resistance.

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    Preparation and Electrochemical Properties of Bamboo Based Ultra-thick Carbonaceous Electrode Materials
    Tingting YU, Zongze LYU, Xiang LI, Jindong HU, Peiyan LI, Zhiguo LI
    2022, 42 (2):  10-18.  doi: 10.3969/j.issn.0253-2417.2022.02.002
    Abstract ( 183 )   HTML ( 1492647935 )   PDF (2188KB) ( 270 )   Save

    The 2.5 mm bamboo charcoal ultra-thick electrode material was prepared by direct carbonization of bamboo which preserved its straight pore structure. The bamboo charcoal materials Z-700, Z-800, and Z-900 were prepared at 700, 800 and 900 ℃, which were characterized by SEM, XPS, Raman spectra analysis. The results showed that the original bamboo structure was maintained after carbonization. Among them, the carbonized sample Z-900 owned a higher BET specific surface area(SBET) of 483 m2/g, total pore volume(Vtotal) of 0.23 cm3/g, mesoporous pore volume(Vmes) of 0.05 cm3/g, and micropore volume(Vmic) of 0.18 cm3/g. Electrochemical performance tests showed that the specific capacitance of the prepared ultra-thick bamboo charcoal electrode Z-900 was as high as 22.0 F/cm2 in the 6 mol/L KOH electrolyte with the current density of 10 A/m2. When the current density was 200 A/m2, the specific capacitance still reached 14.5 F/cm2 and the capacitance retention rate was 65.9%. The symmetric supercapacitor Z-900//Z-900 assembled with ultra-thick bamboo charcoal electrode Z-900 owned a specific capacitance of 14 F/cm2 at the current density of 10 A/m2, which had a discharge time of 3 500 s, an energy density of 4.9 W·h/m2, and a power density of 5 W/m2. At the current density of 100 A/m2, the coulomb efficiency could reach 99.8% after 10 000 cycles, and the capacitance retention was 88%, which demonstrated that Z-900 had an excellent electrochemical stability.

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    Preparation and Properties of Cellulose-based Urushiol Acetal Composite Coatings
    Renjin GAO, Liwei WANG, Yongxin YE, Wenyuan LI, Jianrong XIA
    2022, 42 (2):  19-24.  doi: 10.3969/j.issn.0253-2417.2022.02.003
    Abstract ( 144 )   HTML ( 11823 )   PDF (3309KB) ( 212 )   Save

    Dialdehyde cellulose(DAC) was prepared by the oxidation of celluose with sodium periodate. Then, the condensation reaction of DAC and urushiol was carried out to prepare the cellulose-based urushiol acetal composite coatings. The properties and structure of DAC were characterized by FT-IR, XRD and SEM, while the properties and structure of composite coatings were characterized by FT-IR, TG and SEM. The results showed that DAC was successfully prepared. The properties of the composite coatings changed significantly with the increase of DAC addition. It was found that the composite coating with 20% DAC addition had better comprehensive properties with the surface drying time of 140 min, adhesion(Baige knife method) of 4B, flexibility of 3 mm, glossiness of 26.3%, and the roughness of 2.2 μm. Notably, the acid and salt resistance of the film did not change, but the alkali resistance was improved obviously. The heat stability was improved and the inner structure of the film was denser and more uniform.

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    Cell Morphology and Chemical Composition of Deseeded Sunflower Studied by Fractional Method
    Lizhen WANG, Junyue WANG, Hao REN, Huamin ZHAI
    2022, 42 (2):  25-30.  doi: 10.3969/j.issn.0253-2417.2022.02.004
    Abstract ( 155 )   HTML ( 303175 )   PDF (6515KB) ( 194 )   Save

    The cell morphology and chemical composition of deseeded sunflower were studied by fractional method. The deseeded sunflower could be divided into seven fractions, namely, stalk rind, pith, receptacle, bract, bractlet, petiole and leaf blade. The weight percentage of stalk rind and receptacle were 49.4% and 28.1%, and the other fractions ranged from 3.4% to 5.9% respectively. The pith consisted only of parenchyma cells, while the other fractions consisted of epidermal cells, fibers cells, parenchyma cells, and vessel elements. The fiber volume percentage of stalk rind was 68.4% and the aspect ratio of stalk rind was the largest(38.6) and the stalk rind could be used as the raw material for papermaking. The other fractions were mostly parenchyma cells, and the volume percentage of fine fiber was more than 50%.The holocellulose weight percentages in stalk rind and bractlet were 65.7% and 58.6%, the pentosan weight percentages were 22.2% and 22.5%, and the lignin weight percentages were 22.7% and 16.2%, respectively. The stalk rind and bractlet could be used as biomass raw material of lignocellulosic, and the stalk rind could be used as papermaking raw material. The hot water extractive weight percentages ranged from 26.1% to 50.8% and the benzene-alcohol extractive contents ranged from 3.5% to 8.7% in the stalk pith, receptacles, bracts, petioles and leaf blades, which were needed for further research. The biological structure and chemical composition of each fraction were highly heterogeneous, and the deseeded sunflower fraction processing was its high value-added utilization method.

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    Preparation and Electrochemical Performance of Lignin-based Activated Carbon by Phosphoric Acid Activation
    Qi GUO, Wei XU, Junli LIU
    2022, 42 (2):  31-38.  doi: 10.3969/j.issn.0253-2417.2022.02.005
    Abstract ( 171 )   HTML ( 1703935999 )   PDF (4311KB) ( 278 )   Save

    Mesoporous activated carbon was prepared from poplar lignin by phosphoric acid activation. The effects of activation temperature(400-900 ℃) and mass ratio of phosphoric acid and lignin(impregnation ratio, 1∶1-4∶1) on the structure of activated carbon LAC-x-y(x represented the impregnation ratio, y represented the activation temperature) were investigated by pore structure, XRD and Raman spectroscopy analysis. The relationship between the electrochemical performance of activated carbon and its structure was investigated by means of electrochemical characterization. Pore structure analysis results showed that increasing the temperature and impregnation ratio was beneficial to the formation of mesopore, but too high temperature would lead to the collapse of pore structure, and too high impregnation ratio would lead to the increase of ash content, which would lead to the degradation of the performance of activated carbon. XRD and Raman spectroscopy results showed that increasing the temperature could improve the degree of graphitization of activated carbon, while increasing the impregnation ratio could decrease the degree of graphitization. Under the activation temperature of 800 ℃ and impregnation ratio of 2∶1, the activated carbon LAC-2-800 had the best performance, with specific surface area of 1 031 m2/g, mesopore ratio of 61% and average pore size of 3.31 nm. As the electrode material of supercapacitor, the specific capacitance reached 165 F/g at 1 A/g current density, and 136 F/g at 10 A/g current density. After 5 000 cycles at 1 A/g current density, the specific capacitance value could keep at 78.1% of the initial value.

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    Preparation of Oleocanthal and Oleacein Based on Centrifugal Partition Chromatography Technology and Their Antioxidant Activities
    Wenjun LI, Chengzhang WANG, Jiandu LEI, Fengxia TANG
    2022, 42 (2):  39-46.  doi: 10.3969/j.issn.0253-2417.2022.02.006
    Abstract ( 166 )   HTML ( 895999 )   PDF (5702KB) ( 213 )   Save

    Based on centrifugal partition chromatography(CPC) and thin-layer chromatography(TLC), preparative high performance liquid chromatography(Pre-HPLC) and so on, the total polyphenol extract(TPF) of olive oil was extracted from extra virgin olive oil, and then TPF was used as raw material to separate and prepare 2-(4-hydroxyphenyl) ethyl(E)-4-formyl-3-(2-oxoethyl)hex-4-enoate(oleocanthal, OLEO) and 2-(3, 4-dihydroxyphenyl)ethyl(Z)-4-formyl-3-(2-oxoethyl)hex-4-enoate(oleacein, OLEA) monomer compounds. Their structures were characterized by 1H NMR and their antioxidant activities were also investigated. The results showed that 14 fractions were obtained during the process of CPC with the solvent system of n-hexane/ethyl acetate/ethanol/water volume ratio of 3∶2∶3∶2 from 9 g extract in 20 mL of methanol. After purification, 422.3 mg OLEO and 163.0 mg OLEA with the purity of ≥95% were obtained, respectively; the antioxidant activities of OLEO and OLEA at different concentrations(0-1 g/L) were evaluated by their free radical scavenging capacity on ABTS+·, DPPH· and total antioxidant capacity(T-AOC), it indicated that OLEA had stronger antioxidant activity than OLEO, and the 50% inhibition concentration(IC50) values of OLEO and OLEA for DPPH· were 0.029 and 1.85×10-11 g/L, respectively, the scavenging capacties of OLEO and OLEA against ABTS+· were 0.765 5 and 0.894 2 mmol/L(calculated by the concentration of Trolox); and their total antioxidant capacities reached 0.157 1 and 0.646 2 mmol/L(calculated by the concentration of FeSO4), respectively.

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    Preparation and Electrochemical Performance Analysis of Enzymatic Hydrolyzed Lignin Carbon
    Tingting HU, Shuhui TONG, Jiaqi WEI, Lei ZHANG, Jianing ZHAO
    2022, 42 (2):  47-55.  doi: 10.3969/j.issn.0253-2417.2022.02.007
    Abstract ( 161 )   HTML ( 184222719 )   PDF (2378KB) ( 287 )   Save

    Corn straw enzymatic hydrolyzed lignin carbon LC1, LC2and LC3 were prepared using purified corn straw enzymatic hydrolyzed lignin as carbon source and carbonized at high temperature under N2 conditions for 1, 2 and 3 h. SEM, TEM and nitrogen adsorption/desorption curve were used to analyze the prepared carbon materials. The results showed that LC1, LC2 and LC3 had microporous, mesoporous and macroporous structures with specific surface areas of 894.75, 1 376.74 and 776.47 m2/g, respectively. The pore volumes of the samples were 0.41, 0.70 and 0.40 cm3/g, respectively. XRD and Raman spectrum showed that the order of the enzymatic hydrolyzed lignin carbon increased with the prolongation of carbonization time. XPS analysis showed that the enzymatic hydrolyzed lignin carbon mainly contained C, O and N(small amount) elements. The electrochemical properties of LC1, LC2 and LC3 were tested using a three-electrode system. The results showed that LC2 had the highest specific capacitance of 222.2 F/g at 0.2 A/g current density, and the specific capacitance of LC2 reached 149 F/g at higher current density of 20 A/g. Further study on its practical application in supercapacitors, the results showed that LC2 assembled symmetric supercapacitor had the largest specific capacitance per electrode and the highest capacitance retention(70.2%). At 1 A/g current density, the LC2 supercapacitor showed good rate performance and electrochemical stability after 5 000 charge-discharge cycles. Moreover, a series battery composed of symmetric LC2 supercapacitor could directly light the LED lamp.

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    AlCl3Incorporation Facilitated the Deep Eutectic Solvent Pretreatment
    Jinyuan CHENG, Yunni ZHAN, Chen HUANG, Yongjun DENG, Guigan FANG
    2022, 42 (2):  56-62.  doi: 10.3969/j.issn.0253-2417.2022.02.008
    Abstract ( 138 )   HTML ( 67425 )   PDF (5254KB) ( 218 )   Save

    The paper presented a method for the pretreatment of bamboo wood with AlCl3 assisted eutectic solvent(DES). The DES was synthesized using choline chloride and AlCl3 as the hydrogen acceptors, and guaiacol used as the hydrogen donors. The effects of AlCl3 dosage in DES on the chemical composition and subsequent enzymatic hydrolysis efficiency of the pretreated bamboo were investigated. The results showed that with the increase of AlCl3 dosage, the contents of xylan and lignin decreased gradually with the content of glucan increased in pretreated bamboo, which significantly improved its enzymatic hydrolysis efficiency. Under optimal conditions(the amount of choline chloride, guaiacol and AlCl3 was 25∶50∶1). The conversion rate was 42.84%, the recovery of glucan and xylan were 95.95% and 12.84%, respectively, with 74.88% lignin removal. Compared with the DES treatment without the addition of AlCl3, glucan enzymatic hydrolysis with AlCl3-assisted DES treatment increased from 11.16% to 96.20%. The results demonstrated that AlCl3 could effectively promote the dissolution of xylan and lignin. The pretreated materials were characterized by XRD, SEM, and FT-IR. XRD analysis showed that with the increase of AlCl3 dosage, the crystallinity of the pretreated materials increased gradually, mainly due to the gradual removal of lignin and xylan components, while the cellulose components were not significantly damaged. SEM analysis showed that after pretreatment, the pretreated materials appeared obviously fragmentation and agglomeration. With the increase of AlCl3 dosage, the bamboo components were gradually dissolved and destroyed. The FT-IR analysis results also proved that the increase of cellulose content in the pretreated materials accompanied by the gradual decrease of xylan and lignin.

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    Preparation of Biomass-derived Fe-N-C Porous Carbon Material and Its Catalytic Reduction of Nitrobenzene
    Xing LIU, Zhu YIN, Beili LU, Fengzhen WU, Biao HUANG
    2022, 42 (2):  63-70.  doi: 10.3969/j.issn.0253-2417.2022.02.009
    Abstract ( 209 )   HTML ( 80254975 )   PDF (2435KB) ( 213 )   Save

    Fir sawdust, urea and FeCl3·6H2O were mixed thoroughly at a mass ratio of 1∶[KG-*9]1∶[KG-*9]2 to generate the nitrogen doped porous carbon materials loaded with iron(Fe-N-C) after annealing the mixtures at the temperature of 700-1 000 ℃. The elemental composition, structure and surface properties of the obtained carbon materials at different temperatures were analyzed. Following that, the catalytic performance of the reduction of nitrobenzene were investigated. The results showed that the carbonization temperature had a significant effect on the iron and doped nitrogen species. At 700 ℃, the iron species in Fe-N-C-700 were mainly Fe3O4, whereas the nitrogen species were mainly pyridinic-N and pyrrolic-N. As the temperature rose, the iron species became mostly metallic iron, and a portion of the pyridinic-N was changed to graphitic-N. When the temperature was 900 ℃, the manufactured porous carbon material(Fe-N-C-900) had a Fe content of 43.42% and a N content of 2.19%, of which the graphitic-N was 37.7%, pyridinic-N was 23.8%, pyrrolic-N was 22.9% and oxidized-N was 15.6%. When the reaction duration was 2.5 h at 55 ℃. The conversion and selectivity of catalytic reduction of nitrobenzene were close to 100%.The high catalytic performance of Fe-N-C-900 might be due to the synergistic effect between the high content of iron species and graphite nitrogen formed during the calcination process. When Fe-N-C-900 was used for catalytic reduction of nitroarenes with electron-donating substituents such as methyl, amino or hydroxyl group, the corresponding products might be produced with high conversion and selectivity. In additon, when the nitroarenes contained electron-withdrawing substituents such as chlorine or iodine group, the reaction time must be extended to 4 h, and the conversion rate could reach up to 97.3% with the product selectivity above 99%. It indicated that Fe-C-N-900 had good universality for various substrates. And the catalyst had good stability and magnetic recyclability. After 5 times of recycling, the catalytic performance did not decrease obviously, the nitrobenzene conversion remained at 98.3% with the selectivity of 96.5%.

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    Preparation and Application of Rosin Modified Siloxane-based Flame Retardant
    Zhen HUANG, Shibo WANG, Chunyu REN, He LIU, Xu XU, Zhanqian SONG
    2022, 42 (2):  71-79.  doi: 10.3969/j.issn.0253-2417.2022.02.010
    Abstract ( 170 )   HTML ( 2527359 )   PDF (5101KB) ( 238 )   Save

    In order to enhance the flame retardancy of polysiloxane, a novel flame retardant rosin grafted polysiloxane(RGSO) was synthesized by the amidation reaction of rosin and amino-polysiloxane. The synthesized flame retardant was employed as a part of the soft segment to produce flame-retarding rigid polyurethane foam(RPUF) by "one-pot" process. The flame retardant rigid polyurethane foams(RPUF-1-RPUF-4) were obtained with the rosin amounts of 5, 10, 15 and 20 g. The structure of the flame retardants was characterized by FT-IR and Py-GC/MS. The microstructure, thermal stability, flame retardant property and compressive strength of the RPUFS were analyzed. The results showed that the hydrogenated phenanthrene ring structure of rosin inhibited the gas release of cyclosioxane and promoted the compactness of the silica-rich carbon layer, and invested the materials with excellent flame retardant since it become shielding layer coated on the substrate surface and effectively insulated thermal and oxygen flame retardant. Compared with unmodified RPUF(P-RPUF), the limited oxygen index(LOI) value of the modified sample(RPUF-3) increased by 37.1%, and the peak heat release rate(PHRR) of the modified sample decreased by 44.8%. The fire growth rate(FIGRA) of the modified materials decreased from 10.99 kW/(m2·s) to 4.33 kW/(m2·s), which indicated that the introduction of RGSO could significantly enhance the flame retardant performance of RPUF. Meanwhile, the rigid hydrogenated phenanthrene ring structure of rosin improved the compressive strength of the modified RPUF. The compressive strength of RPUF-4 was 366.7 kPa, which was higher than that of S-RPUF(112.5 kPa).

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    Investigation on Degradation of Cellulose to Formic Acid Catalyzed by Molybdenum-vanadium Polyoxometalates
    Xiuqiang CHEN, Xixin DUAN, Junyou SHI
    2022, 42 (2):  80-86.  doi: 10.3969/j.issn.0253-2417.2022.02.011
    Abstract ( 134 )   HTML ( 2561023 )   PDF (692KB) ( 234 )   Save

    Using the synthesized molybdenum-vanadium homopolyacid Na6[α-Mo6V2O26]·16H2O as catalyst and p-toluene sulfonic acid as acid catalyst, the catalytic performance of the molybdenum-vanadium homopolyacid for the selective conversion of cellulose to formic acid(FA) was investigated under aqueous medium and O2 atmosphere. The experimental results showed that the synthesized molybdenum-vanadium homopolyacid exhibited strong oxidizing property. Under the conditions of 0.2 g of cellulose, 0.1 g of Na6[α-Mo6V2O26]·16H2O, 0.15 g of p-toluene sulfonic acid, 10 mL of deionized water, O2 pressure of 1 MPa, and temperature of 140 ℃ were reacted for 3 h, the conversion rate of cellulose reached 98%, and the yield of formic acid was 47%. In addition, catalytic performance of the catalyst for the conversion of monosaccharides(xylose and glucose) into formic acid was studied, and the conversion of xylose to formic acid had the highest yield of 63%.

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    Prerparation and Performance of Composite of Cellulose Nano-fiber(CNF)/Montmorillonite(MMT)
    Yujia YANG, Xiaojing LUO, Lanbo OU, Shujun TAN, Chen YANG, Zhaoyun LIN
    2022, 42 (2):  87-92.  doi: 10.3969/j.issn.0253-2417.2022.02.012
    Abstract ( 171 )   HTML ( 345775 )   PDF (2047KB) ( 186 )   Save

    Cellulose nanofiber(CNF) was used as raw material, and then was blended with the modified montmorillonite(MMT) by cetyltrimethylammonium bromide(CTAB) to prepare CTAB@MMT-CNF. The effect of CTAB dosage on the properties of CTAB@MMT-CNF was explored, and CTAB@MMT-CNF was characterized by FT-IR, morphology analysis and thermal gravimetric analysis. Subsequently, the effects of composite and their dosage, and the concentration of methylene blue on the removal performance of methylene blue were investigated. The results showed that the dosage of CTAB would affect the compounding of CNF and CTAB@MMT, and more CNF would insert into the interlayer structure of MMT with 20% CTAB. It was also found that CTAB@MMT-CNF showed the best removal performance and the highest removal efficiency of methylene blue of 99.94% when 10 mL methylene blue solution(600 mg/L) was treated with 25 mg CTAB@MMT-CNF, in which the dosage of CTAB was 15%. Otherwise, this process was accorded with pseudo first order rate equation, its apparent constant was 0.025 7 s-1 and the correlation coefficient was 0.965 3.

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    Analysis of Gel Change of Urea-formaldehyde Resin with Low Molar Ratio
    Ji LI, Yifu ZHANG, Tao XIONG, Xin SUN, Saiqing XIE
    2022, 42 (2):  93-100.  doi: 10.3969/j.issn.0253-2417.2022.02.013
    Abstract ( 100 )   HTML ( 15560 )   PDF (2773KB) ( 187 )   Save

    Using formaldehyde and urea(F and U, molar ratio 1:1) as raw materials, stable urea-formaldehyde resin(UF) with low F/U was synthesized by "alkali-acid-base" method. The effects of storage time, neutral electrolytes(NaCl, MgCl2) and acidic electrolytes(NH4Cl, AlCl3) on UF were investigated. The storage stability, potential stability and aggregation of UF colloidal particles were analyzed by Zeta potentiometer, laser particle size analyzer(LS), scanning electron microscope(SEM-EDS) and field emission transmission electron microscope(FE-TEM), by which the gel rule of UF was revealed. The results showed that the gel of UF not only embodied the colloidal properties, but also had chemical reaction. Both ions and free formaldehyde restricted the stability of UF. The increase of aggregate size led to the gel of UF. The gel time was related to the type of electrolyte. SEM-EDS and Zeta potential tests showed that the higher ionic species content on the surface of colloidal particles might contribute to the electrostatic stability of colloidal particles; neutral electrolytes had limited effect on the stability of colloidal particles, while acidic electrolytes obviously changed the stability of colloidal particles; the acidic conditions provided by acidic electrolytes promoted the reaction between monomers and linear oligomers in the soluble continuous phase, resulting in the formation of larger size aggregates, leading to the advance of gel. The results of FE-TEM and PSD showed that the gel process of UF might be accompanied by the fusion of colloidal particles. Namely, small particles disappear, while large particles grew accordingly, and eventually developed into larger aggregates until the formation of gel with the consumption of oligomers.

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    Synthesis and Characterization of Waterborne UV Curable Resin fromEpoxy Itaconate Modified by Isocyanate
    Junna BIAN, Jian CHEN, Zhaozhe YANG, Guomin WU, Zhenwu KONG
    2022, 42 (2):  101-109.  doi: 10.3969/j.issn.0253-2417.2022.02.014
    Abstract ( 197 )   HTML ( 1116209151 )   PDF (885KB) ( 236 )   Save

    Epoxy itaconate resin(IE) was synthesized by esterification of itaconic acid(IA) with epoxy resin E51. The IE was then reacted with different half-terminated isocyanates to prepare epoxy itaconate resin modified with isocyanate(DIHIE) in order to improve the UV curing activity. In next, the chemical structure and particle size distribution of IE and DIHIE were characterized by FT-IR, 1H NMR and laser particle sizer. The results showed when the molar ratio of carboxyl group to epoxy group was 2∶[KG-*9]1, the reaction temperature and time was 90 ℃ for 4 h, and the amount of catalyst N, N-dimethylbenzylamine was 3% of the total amount of reactants, while the conversion rate of the IA was about 95%. The half-terminated isocyanate intermediate was synthesized from isophorone diisocyanate(IPDI) and hydroxyethyl methacrylate(HEMA), and then it reacted with IE to obtain IPDIHIE. IPDIHIE was synthesized with acetone as solvent, which was carried out at acetone reflux temperature(56 ℃) for 8 h. The storage stability of the DIHIE dispersion was better when triethanolamine(TEOA) was used as neutralizing agent. The UV curing activity of the resins were improved obviously after being modified by half-terminated isocyanate. The curing time was shortened from 100 s to less than 60 s after modification. The pencil hardness of paint film could reach 4H and the adhesion performance was excellent. Moreover, all of them were about 1 grade.

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    Study on the Synthesis of Thujopsane-8, 9-diol from Thujopsene
    Sheng ZHANG, Kai ZHU, Ping MAO
    2022, 42 (2):  110-114.  doi: 10.3969/j.issn.0253-2417.2022.02.015
    Abstract ( 146 )   HTML ( 24199 )   PDF (483KB) ( 147 )   Save

    Thujopsane-8, 9-diol was synthesized by the dihydroxylation of thujopsene using KMnO4 as oxidant, tertiary-butyl alcohol/H2O(2:1, volume ratio) as solvent in the presence of NaOH. The effects of reaction conditions on the dihydroxylation reaction were investigated and the optimal reaction conditions were reaction temperature 40 ℃, molar ratio of raw materials n(KMnO4): n(thujopsene)=1.8:1, reaction time 3 h, mass fraction of KMnO4 aqueous solution 5%. Under these conditions, the conversion rate of thujopsene was 98.3%, the yield and selectivity of thujopsane-8, 9-diol were 88.7% and 90.2%, respectively. The structure of the product was characterized by GC-MS, FT-IR and 1H NMR, and confirmed to be thujopsane-8, 9-diol.

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    Preparation and Antioxidant Effect of Zanthoxylum bungeanum Leaves and Potentilla fruticosa Leaves Extracts Compound Beverage
    Ruofei ZHENG, Zijia LIU, Nuernisa KASIMU, Dongmei WANG
    2022, 42 (2):  115-124.  doi: 10.3969/j.issn.0253-2417.2022.02.016
    Abstract ( 177 )   HTML ( 23701503 )   PDF (960KB) ( 178 )   Save

    The Zanthoxylum bungeanum leaves extracts(ZBE) and Potentilla fruticosa leaves extracts(PFE) were prepared by ultrasonic assisted extraction and macroporous adsorptive resins, and the optimal mixing ratio was determined by isoradiation analysis. The results showed that the mixture of ZBE and PFE(mass ratio 3:1) exhibited the strongest synergistic antioxidant interaction. The formulation of ZBE and PFE compound beverage was as follows: the mixture of ZBE and PFE(3:1) 0.10%, xylitol 0.015%, aspartame 8.00%, citric acid 0.10%, CMC-Na 0.30%, xanthan gum 0.02%, and β-cyclodextrin 0.40%, 0.05% potassium sorbate. After boiling sterilization for 30 min, the total colonies numbers, mold and yeast numbers, coliform numbers, and foodborne pathogenic numbers of beverage were all meet the national standards, the total phenol content(TPC) was 0.014 1 μmol/g, the total flavonoid content(TFC) was 0.019 8 μmol/g, the content of the six main components catechin, ferulic acid, hypericin, rutin, quercitrin and afzelin were(28.76±0.20), (13.72±0.16), (65.32±0.55), (19.85±0.27), (62.76±0.36), (16.78±0.22) mg/g, the ABTS+· free radical scavenging capability was (2.09±0.011) μmol/g, the FRAP trivalent iron reduction capacity was (1.21±0.003) μmol/g, the mass concentration of the samples required to removing 50% DPPH·(IC50) was (436.48±3.16) mg/L, it exhibited strong antioxidant effects. Furthermore, after chemical stability test and the prediction and verification tests of shelf life, the shelf life at (25±2) ℃ was 6 months.

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    Research Progress in the Modification of Bio-based Poly(Ethylene 2, 5-Furandicarboxylate)
    Xiaoqing LIN, Shunhui TAO, Lei HU, Xiaojie ZHENG, Xiaodong ZHANG, Yao LIU
    2022, 42 (2):  125-136.  doi: 10.3969/j.issn.0253-2417.2022.02.017
    Abstract ( 617 )   HTML ( 1923910146 )   PDF (695KB) ( 391 )   Save

    With the depletion of petroleum resources and the increasingly serious white pollution, the preparation of bio-based poly(ethylene 2, 5-furandicarboxylate)(PEF) from lignocellulosic resources has become one of the research hotspots in the fields of biorefinery and green chemical industry. Compared with petroleum-based plastics, such as poly(ethylene terephthalate)(PET) and polycarbonate(PC), PEF not only has excellent thermal properties and mechanical strength, but also has more obvious advantages in gas barrier properties, which is considered as a perfect substitute for PET. However, PEF also has some drawbacks, including low elongation at break, dark color, difficult degradation and slow deep crystallization speed. Therefore, it is necessary to modify PEF before practical application. In this paper, the research progresses of PEF modification, including copolymerization, blending and other modification methods were reviewed. The effects of different diols or diacid modified monomers, catalyst types, reaction modes, additives on the properties of PEF were summarized, and the developing trend and application prospects of modified PEF were discussed.

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