Table of Content

30 March 2017, Volume 51 Issue 2 Previous Issue    Next Issue

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Synergistic Effect of Environmental Ca-Zn Composite Thermal Stabilizer and Plasticizer on Poly(vinyl chloride) LI Mei, DING Chengxiang, CHEN Jie, ZHU Jinhua, WANG Mei, XIA Jianling 2017, 51 (2):  1-7.  Abstract ( 730 )   PDF (1223KB) ( 894 )   Save The self-made rubber seed oil-based epoxy fatty acid methyl ester(ERSO) was used as plasticizer and the oil-based polyacid calcium-zinc composite(OMFCTS) was used as thermal stabilizer. Then the combination of ERSO and OMFCTS was used in PVC modification with β-diketone as co-stabilizer. The thermal and mechanical properties of eight modified poly(vinyl chloride) (PVC) blends were determined by means of the heat aging test methods,Congo-red test,TGA,TGA-FTIR,TGA-MS,tensile test and DMA. The results showed that the PVC blends with ERSO/OMFCTS had the optimal thermal stability,good mechanical properties,and lower glass transition temperature(Tg,38.2℃) than that of the PVC blends with DOP/CaSt2/ZnSt2,ERSO/CaSt2/ZnSt2 or DOP/OMFCTS. And its static thermal stability time at 200℃ was 46'21" and the tensile elongation at break was 265.6%. It could be concluded that there was an obvious synergistic effect between ERSO and OMFCTS,and the ERSO/OMFCTS could replace the tradational plasticizer dioctyl phthalate and calcium/zinc stability of stearic acid(CaSt2/ZnSt2) effectively. References | Related Articles | Metrics

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Alkali Catalytic Facile Hydrothermal Depolymerization of Enzymatic Hydrolysis Lignin SHAN Zengyu, MA Zhuoming, LI Shujun 2017, 51 (2):  8-12.  Abstract ( 771 )   PDF (821KB) ( 819 )   Save Aiming at the shortcomings of lignin like high molecular weight,high steric hindrance,low reactivity and difficulty in utilization,the enzymatic hydrolysis lignin(EHL) was mildly hydrothermal depolymerized with NaOH as catalyst. The effects of process parameters,including reaction temperature,reaction time,NaOH/lignin ratio and lignin mass fraction,on lignin depolymerization were investigated. The lignin samples were characterized by FT-IR,1H NMR and GPC. The operating conditions were optimized as 200℃,120 min,and NaOH/lignin ratio 0.2 with 8% lignin. This led to the highest yield of depolymerized lignin (71%). FT-IR analyses demonstrated that the aromatic structure of lignin was remained under mildly hydrothermal degradation conditions. The results of 1H NMR indicated that some ether bonds in lignin were interrupted and new phenolic hydroxyl groups were generated. GPC analyses showed that the molecular weight of lignin decreased significantly and the lignin was notably degraded. References | Related Articles | Metrics

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Effects of Preparation Technology on Mechanical Properties of Lignin-based Elastomers SUN Yunchang, GAO Zhenhua, WANG Xiangming 2017, 51 (2):  13-18.  Abstract ( 573 )   PDF (776KB) ( 790 )   Save A lignin-based elastomer was prepared by the reactions of polyether polyol and lignin with concentrated sulfuric acid as catalyst. The effects of polyol/lignin mass ratio,polyol combination(mass ration of PEG and PPG),the dosages of catalyst and glycerol,the reaction temperature and the curing time on the mechanical properties of lignin-based elastomers were investigated. The results indicated that the tensile strength of lignin-based elastomers increased with the increases of lignin content,polyether polyol content,sulfuric acid content,the liquefying temperature and the curing time,but the tensile elongation rate reduced. A certain level of glycerol could increase the mechanical strength,but too much glycerol would lead to opposite effect. Through balancing tensile strength and elongation rate,the optimal process conditions of elastomer were polyol/lignin mass ratio 1.8:1,PEG and PPG mass ratio 1:1.2,catalyst content 2%,glycerol content 10%,reaction temperature 120℃ and curing time 10 h. Under these conditions,the tensile strength was 3.64 MPa and the tensile elongation rate was 173%. FT-IR results showed that the mixture of lignin,PEG,PPG and concentrated sulfuric acid did not react without high temperature. And during liquefaction, esterification reaction occurred in the mixture under high temperature. The reaction degree was improved under the condition of high temperature curing,and at the same time the alkylation reaction and condensation reaction occurred. References | Related Articles | Metrics

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Reductive Amination of Levulinic Acid to 5-Methyl-2-pyrrolidone WANG Yanjun, LI Zheng, JIANG Yetao, CHEN Wei, ZENG Xianhai, SUN Yong, LIN Lu 2017, 51 (2):  19-25.  Abstract ( 733 )   PDF (538KB) ( 989 )   Save The reductive amination of levulinic acid with ammonium formate as hydrogen and nitrogen donor to synthesize 5-methyl-2-pyrrolidone(5-MeP) in DMF solvent was developed and the mechanism of this process was proposed. The effects of various reaction conditions including temperature,reaction time,mass fraction and molar ratio of levulinic acid with ammonium formate and pH value on 5-methyl-2-pyrrolidone yield were investigated. Meanwhile,different solvents and levulinate derivatives were investigated in this system. The results showed that the properly increasing temperature,reaction time,the molar ratio and total mass fraction of levulinic acid and ammonium formate,and the pH value of system could improve the yield of 5-methyl-2-pyrrolidone. The polar aprotic solvents including formamide,DMA,DMSO and levulinate derivatives,such as methyl levulinate and α-angelica lactone,could also be respectively used as solvents and substrates in this system,too. References | Related Articles | Metrics

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Synthesis and Catalytic Activity of Double Bond Ionic Liquids for Biodiesel Production CAI Shaoxiong, ZHANG Hui, ZHENG Deyong 2017, 51 (2):  26-30.  Abstract ( 645 )   PDF (810KB) ( 872 )   Save A new acidic ionic liquids with double bond ([SO3H(CH2)4VIm] [CF3SO3]) was synthesized and used in the esterification reaction of oleic acid to synthesize biodiesel. The effects of reaction conditions on the catalytic synthesis were investigated. The results showed that the optimum conditions were the molar fraction of ionic liquid to oleic acid 5%,molar ratio of methanol to oleic acid 6:1,60℃ and 5 h. Under these conditions,the yield of product was more than 96.07%. The ionic liquid catalyst exhibited a good catalytic activity,and after it was reused five times,the yield of product was over 95%. References | Related Articles | Metrics

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Improvement of Preparation Process and Characterization of Liquefied Rice Straw Based Polyurethane Foam FU Wenxing, WANG Dun, WANG Wanyu, ZHANG Yucang 2017, 51 (2):  31-36.  Abstract ( 517 )   PDF (871KB) ( 840 )   Save The water-blown polyurethane form(PUF) was produced with liquefied rice straw as raw materials,N,N,N,N,N-pentamethyl diethylenetriamine(P5) and N,N-dimethyl cyolohexlemine(P8) as co-catalyst. Physicochemical properties of the prepared polyurethane foams were investigated. Then the optimum preparation conditions were confirmed. Material testing machine,thermogravimetric analysis(TGA),Fourier transform infrared spectrometer(FT-IR) and scanning electron microscope(SEM) were conducted to characterize the mechanical properties,thermal stabilities,chemical structures and microstructures of the polyurethane foam. The results showed that the optimum preparation conditions were water content 2%,the proportion of co-catalyst 2%,mass ratio of P5 and P8 in co-catalyst 1.5,isocyanate index 1.2 and the dosage of foam stabilizer(silicone oil B8462) 4%. Under these conditions,the tensile strength and compressive strength of the product with density of 40 kg/m3 were 309 kPa and 154 kPa,respectively. The mechanical property of the synthesized liquefied rice straw based polyurethane foam was better than that of the sample derived from organotin and tertiary amine. In addition,the synthesized polyurethane foam had good thermal stability. References | Related Articles | Metrics

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Co-pyrolysis Characteristics of Caragana korshinskii Kom. and Low-rank Coal Blends WU Yanwei, GONG Juhui, SHAO Tingting, GAO Xueyi, WANG Kebing 2017, 51 (2):  37-42.  Abstract ( 648 )   PDF (1800KB) ( 808 )   Save The co-pyrolysis characteristics and interaction effect of four kinds of low rank coals abound in Inner Mongolia with Caragana korshinskii Kom.(NT) were investigated by using the thermo-gravimetric apparatus. The experimental results showed that the co-pyrolysis interaction trend of different varieties of coal and NT was only different in the middle temperature range. The mixing ratio affected the size of the co-pyrolysis interaction and didn't affect the interaction trend of the whole process. According to the data of the action rate(Δα),the interaction effects of co-pyrolysis process could be divided into 4 stages. The temperature period of violent weight loss of desert shrub corresponded to the first and second stage. During these two stages,the coal inhibited the effusion of the volatile of NT firstly and then the volatile of NT promoted the pyrolysis of the coal. In the third stage of the pyrolysis of NT coke,the synergistic or inhibitory interactions between desert shrub coke and coal were influenced by coal species. Finally,in the high temperature section of co-pyrolysis process,NT ash minerals promoted the coal pyrolysis. References | Related Articles | Metrics

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Optimization of Activation Conditions of High-performance Activated Carbon from Coffee Shell by Response Surface Methodology LIU Ping, WANG Hongbin, LI Guizhen, YANG Min, FANG Xiuying 2017, 51 (2):  43-47.  Abstract ( 551 )   PDF (775KB) ( 817 )   Save The activation conditions for the preparation of high-performance activated carbon with coffee shell as raw material and KOH as activating agent were optimized. The effects of the activated time,activated temperature and alkali-to-carbonized material ratio(mass ratio of KOH and carbonized material of caffee shell) on the iodine adsorption capacity were explored by single factor test and the response surface methodology. The optimum activation conditions for preparing activated carbon from carbonized material of coffee shell were activated time 5 min,activated temperature 950℃ and alkali-to-carbonized material ratio 4:1. The experimental and predicted results of the iodine adsorption value were 2 214 mg/g and 2 209.5 mg/g,respectively.They were basically consistent. This verified the efficiency of the model. References | Related Articles | Metrics

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Review of Reforming Technology of Biomass Gasification WANG Xiao, GAO Ningbo 2017, 51 (2):  48-56.  Abstract ( 623 )   PDF (665KB) ( 867 )   Save The research progress in the reforming technologies of biomass gasification including the catalytic gasification method and the high temperature agent gasification method was introduced. The latest studies of reforming catalyst were discussed and reviewed. This particularly focused on the application of the natural mineral catalyst,nickel-based catalysts and precious metal catalysts in biomass gasification. Besides,the matters of catalyst deactivation in the industrial application existing in catalytic reforming of biomass gasification were analysed. The technologies of high temperature agent gasification,including the high temperature air gasification technology and high temperature steam gasification,were presented,too. Finally,the priority of biomass gasification and future direction were summarized. References | Related Articles | Metrics