Journal of the Taiwan Institute of Chemical Engineers
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2018
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IF 3.849
Yuanfeng Wu,Xianghai Song,Jiahui Zhang,Shuai Li,Xinghui Yang,Huazheng Wang,Ruiping Wei,Lijing Gao,Jin Zhang,Guomin Xiao
A series of Ce 1- x Cd x O mixed oxide catalysts prepared by co-precipitation method were tested for synthesis of glycerol carbonate (GC) from glycerol and diethyl carbonate (DEC). The microstructural and physicochemical properties of the bimetal catalysts were characterized by XRD, SEM, TEM, XPS, CO 2 -TPD, N 2 -adsorption, TG-DSC and 1 H NMR. The results show that the spherical particles of CdO were uniformly dispersed on the surface of lamellar CeO 2 . Besides, a noticeable increase was observed in the moderate basic sites concentration, because more oxygen atoms were adsorbed on the bimetal sample surface which was attributed to Ce 4+ doped into CdO lattice. The Ce 0.7 Cd 0.3 O sample annealed at 500 °C was observed with the highest catalytic activity. 96.84% of glycerol conversion and 100% selectivity to GC were obtained over this catalyst under the optimized conditions (5 wt.% catalyst of glycerol, 90 °C, 180 min, glycerol/DEC molar ratio of 1:3). Besides, it was found that the conversion of glycerol carbonate was synergistically accelerated by the moderate and strong basic sites.
研究领域:
催化化学
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材料科学
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绿色化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
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2018
·
IF 0
Yanan Liang,Kunmei Su,Lei Cao,Zhenhuan Li
Lithium doped TiO 2 were prepared by simple impregnation, which was used as heterogeneous catalysts for the transesterification of DMC with BPA. The characterized results of FTIR, XRD, XPS, SEM, TEM and temperature programmed desorption of CO 2 (CO 2 -TPD) showed that the structure and performance of the catalysts were obviously influenced by the doping amount of Li + and calcining temperature. The optimum catalytic activity was obtained when the molar ratio of Ti/Li reached 6 and the calcination temperature came up to 400 ℃, which was due to Li + reaction with TiO 2 to form surface Ti-O-Li at 400 ℃ (Ti/Li-6-400). When the transesterification of DMC with BPA was carried out at 160–180 ℃ over Ti/Li-6-400, BPA conversion reached 46.67%, and the yields of one-methylcarbonate-ended-BPA (MmC(1)) and two-methylcarbonate-ended-BPA (DmC(1)) achieved 36.36% and 5.97%, respectively, and only 9.3% methylation selectivity was detected. In addition, the possible transesterification mechanism was provided.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 6
·
IF 1.866
Guang Chai,Dongcheng Sun
A new reactive polyurethane/polyacrylate (PU/PA) blend was developed by mixing a core–shell polyacrylate latex containing keto groups in shell layer and a polyurethane dispersion incorporating multiple hydrazide groups which was synthesized by introducing the poly-hydrazide groups into the end of the vinyl-terminated polyurethane chains. Fourier transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC) results indicated that poly-hydrazide groups had been incorporated in the polyurethane chains. Transmission electron microscopy (TEM) micrograph revealed that polyacrylate particles had a clear core–shell structure. The results of FTIR, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) indicated that the crosslinking reaction between two polymer systems had happened and crosslinking structure could effectively improve the compatibility between PA and PU. Thermogravimetric analysis (TGA) and mechanical tests results suggested that crosslinking structure could enhance the thermal stability and mechanical properties of blends. The influence of the PA content and the n( CO )/n( NHNH 2 ) ratio on the hardness, water resistance, solvent resistance, and gel fraction of the blend films were comprehensively studied. The optimal PA content and n( CO )/n( NHNH 2 ) ratio was 30% and 1.5:1 in this experiment, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44443.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
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2016
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IF 3.611
Zhenhuan Xiao,Huacong Zhou,Jianmin Hao,Hailong Hong,Yinmin Song,Runxia He,Keduan Zhi,Quansheng Liu
As the fast depletion of coal resources, exploring the value-added utilization approaches of low rank coals or their components and, in parallel, promoting the conversion of sustainable resources (such as biomass) into useful chemicals are critical issues facing human society. In this work, we used humic acids (HAs), an abundant material in nature (mainly derived from low rank coals), and the transition metal zirconium (Zr) to prepare a novel Zr-containing hydrogen transfer catalyst. The prepared catalyst was applied into the conversion of biomass-derived ethyl levulinate (EL) into gamma-valerolactone (GVL) via hydrogen transfer reaction. Both the preparation conditions of the catalysts and the reaction parameters during the conversion of EL into GVL were systematically investigated. The catalyst was characterized by SEM, TEM, FTIR, powder XRD, and TG analysis. The results demonstrated that the as-prepared catalyst was highly efficient for the conversion of EL into GVL. Under optimized conditions, EL could be completely converted and the GVL yield could reach up to 88.3%. The catalyst could be used at least 11 times without notable changes in both activity and structures, indicating an excellent stability. As far as we know, this is the first work using HAs to prepare Zr-containing catalyst and its application to the conversion of EL into GVL in biomass utilization.
研究领域:
化学工程
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可再生能源
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
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2017
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IF 4.811
Xi Chen,Nan Zheng,Qiao Wang,Lingzhi Liu,Yongfeng Men
The differences in side chain crystallization behavior between cellulose esters (CEs) and hydroxypropyl cellulose esters (HPCEs) were systematically investigated by a combination of differential scanning calorimetry (DSC) and small and wide-angle X-ray scattering techniques. DSC investigation indicated that under the same side chain length, the fusion enthalpy and the number of crystallized CH 2 of CEs were smaller than HPCEs. At the same time, their d-spacing and molecular arrangements were also different from each other. For the CEs, the side chains are perpendicular to the main chain, while the side chains most probably tend to tilt to main chain in the HPCEs as was evidenced by X-ray scattering results. The phenomenon can be understood as a consequence of different flexibility of attachment bridges in both kinds of side chain polymers and the steric hindrance of methyl group in the hydroxypropyl group in HPCEs. In addition, the added hydroxypropyl substituents make the side chain length increasing.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 94
·期 1
·167-177
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IF 2.587
Xuejuan Cao,Junnan Wei,Huai Liu,Xinyue Lv,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Shijie Liu,Lu Lin
BACKGROUND γ-Valerolactone (GVL) is a versatile biomass-derived platform molecule that could serve as a building block to produce chemicals, materials and fuels, but the production of GVL from biomass via a cost-competitive method is challenging. In this contribution, a robust Cu─Mg oxide was prepared as an efficient bifunctional catalyst for both H 2 production by MeOH reforming and hydrogenation of methyl levulinate (ML) to GVL in MeOH medium. RESULTS Cu 0.87 Mg 0.13 O x prepared by a urea hydrolysis method offered a GVL yield up to 90.6% at 220°C in 4 h without external hydrogen. This catalyst could be reused for at least seven consecutive cycles without loss of its activity. Notably, Cu 0.87 Mg 0.13 O x also provided nearly 70% GVL yield in methanolysis products of cellulose in the presence of humins. Characterization of the catalyst indicates that the incorporation of MgO greatly facilitates the stabilization of Cu + species that possess a better catalytic performance in ML hydrogenation compared with metallic Cu. CONCLUSION This robust Cu 0.87 Mg 0.13 O x could greatly contribute to develop a highly facile and desirable two-step strategy for GVL production from cellulose, through the integration of ML production by methanolysis of cellulose, H 2 formation by MeOH reforming and ML hydrogenation in MeOH medium. © 2018 Society of Chemical Industry
研究领域:
化学工程
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可再生资源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2018
·Vol. 34
·期 4
·578-583
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IF 1.248
Song Menglu,Yang Xiangui,Wang Gongying
Polycarbonate diols(PCDLs) with a number average molecular weight( M n ) of 2800 and a narrow polydispersity index(PDI=1.33) were synthesized from dimethyl carbonate(DMC) and 1,4-butanediol(BD) via a two-step process. The influences of the molar ratios of DMC to BD in the feedstock, polycondensation temperature and polycondensation time on the PCDLs preparation were studied. CH 3 COONa showed the best catalytic performance among the catalysts studied. The highest BD conversion of 73.8% and PCDLs yield of 64.7% were achieved under its optimum reaction conditions. Furthermore, based on the results of 1 H NMR, the relationships between the ratio of end groups (—OCH 3 /—OH) of oligomers, the M n and chainend constitute of resultant polycarbonates were also investigated. The results indicate that PCDLs can be synthesized when the oligomers mostly bear hydroxyl end groups. In contrast, it was impossible to prepare PCDLs when the oligomers were enriched with methyl carbonate end groups.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
·
IF 4.521
Yajin Li,Jiaxiong Liu,Dehua He
The trans-esterification of glycerol and dimethyl carbonate (DMC) for the synthesis of glycerol carbonate was investigated over a series of Li-La 2 O 3 catalysts with different Li contents under mild reaction conditions. Li-La 2 O 3 catalysts were prepared by simple precipitation and impregnation methods, and characterized using ICP, XRD, BET, XPS, CO 2 -TPD and TEM techniques. It was found that the basicity of La 2 O 3 was obviously changed and the interaction between Li and La 2 O 3 occurred after doping Li component, and the catalytic activity of Li-La 2 O 3 was highly relevant to the strength and content of basic sites on the catalysts. Li doping influenced the crystal phase growth of La 2 O 3 , and also changed the exposed crystal planes of the Li-La 2 O 3 catalysts. The highest catalytic performance was obtained over 3.50Li-La 2 O 3 catalyst calcined at 600 °C for 5 h. The glycerol conversion of 94.4% and glycerol carbonate selectivity of 92.1% were obtained over this catalyst under the proper reaction conditions of 85 °C, 3 h, and the molar ratio of glycerol and DMC being 1/3 with using 0.1 g 3.50Li-La 2 O 3 catalyst.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
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2018
·
IF 2.955
Guoxiong Dai,Qingyi Xie,Shanshan Chen,Chunfeng Ma,Guangzhao Zhang
Being biodegradable and eco-friendly, polyesters are promising in marine anti-biofouling. However, the slow degradation and poor adhesion limit their applications. In the present work, we have prepared poly(ester)-poly(methyl methacrylate) copolymer via radical ring-opening copolymerization of 2-methylene-1,3-dioxepane (MDO) and methyl methacrylate (MMA). The copolymer coating has good adhesion to substrate due to the incorporation of MMA moieties. The main-chain ester bonds from MDO enable the copolymer to enzymatically and hydrolytically degrade, and the degradation rate increases with the ester content. The polymers can serve as a carrier and controlled release matrix for organic antifoulant 4,5-dichloro-2-octylisothiazolone (DCOIT), and the release rate increases with the ester content. Marine field test shows the system of the copolymer and DCOIT has excellent antifouling performance for more than 3 months.
研究领域:
材料科学
·
海洋生物学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 11
·1152-1161
·
IF 2.804
Shi Lei,Zhang Ruo-Yu,Ying Wu-Bin,Hu Han,Wang Yu-Bin,Guo Ya-Qian,Wang Wen-Qin,Tang Zhao-Bin,Zhu Jin
Thermoplastic poly(ether-ester-urethane)s were synthesized from poly(L-lactide) diols (PLLA diols), polytetrahydrofuran diol (PTMG diols), 4,4′-dicyclohexylmethane diisocyanate (HMDI), and 1,4-butanediol (BDO) by a two-step reaction, and the morphology and property of the resultant TPU could be adjusted by varying the PLLA contents. The soft segment was composed of PLLA and PTMG diols. By controlling the percentage of PLLA in the soft segment, the glass transition temperature and mechanical properties of the polyurethanes could be regulated. Based on the FTIR spectrum, we found that two kinds of hydrogen bonding existed individually in soft matrix and hard domain. The hydrogen bonding in soft matrix was unstable, which could be destroyed during elongation. With in situ stretching WAXS and SAXS experiments, we found that the PLLA crystal was destroyed and the PLLA domain oriented along the stretch direction. Finally, we proposed a schematic model to illustrate the microstructures of these elastomers before and after stretch.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2018
·
IF 2.975
Xian-hai Hu,Xiang Liu,Man-li Liu,Gen Li
A red fluorescent sulfonated waterborne polyurethane-based dye WPU-DR11 was synthesized by conjugating Disperse Red 11 (DR11) into polyurethane backbones. The expected structure of WPU-DR11 was characterized by FT-IR and UV–vis spectra. Containing the well-known dye of anthraquinone chromophores , WPU-DR11 exhibits intriguing optical behaviors. Compared with DR11, WPU-DR11 shows an obvious bathochromic shift in absorption spectra , whereas a evident hypsochromic shift in emission spectra. The fluorescence intensity of WPU-DR11 is dramatically enhanced compared with that of DR11. The fluorescence intensity of WPU-DR11 increases with the temperature, which is different from that of ordinary fluorescent materials. It is found that the fluorescence intensity of WPU-DR11 gradually increase with the increase of concentration, and then decrease. Migration rate of WPU-DR11 are only 2.0–4.0%, which is well below migration rate of DR11. The polyester fibers dyed with WPU-DR11 show high color yield, excellent breaking strength retention, good air permeability and anti-wrinkle resistance. According to the experimental results, WPU-DR11 exhibits excellent fluorescent and dyeing performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2017
·
IF 2.726
Hui Ding,Wenjing Ke,Dan Zhao,Lulu Wang,Yujie Gao,Shejiang Liu
In this work, we measured the isobaric vapor-liquid equilibrium (VLE) data for the binary system of methyl caprate (1) + methyl laurate (2) at 2,4 and 6 kPa with a modified Othmer still. The point consistency test of Van Ness test method was applied to check the thermodynamic consistency of all the experimental values, which guaranteed the reliability of our measurements. Afterwards, the experimental data were regressed by two activity coefficient models (Wilson, NRTL). Furthermore, we made the data prediction with the group contribution method (UNIFAC) and the COSMO-SAC model. The results of all the regressions and predictions are satisfying and reasonable, while the results provided by the NRTL model are relatively better than the other three models, with the root mean square deviations of temperature and vapor-phase mole fraction less than 0.33 K and 0.0069, respectively.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）