Catalysts
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2017
·Vol. 7
·期 10
·300
·
IF 3.082
Yi-Ming Ren,Mao-Dong Xu,Xiong Wang
An efficient procedure has been researched for the solvent-free synthesis of bis(indolyl)methanes via a one-pot reaction of indoles and aldehydes or ketones promoted by PEG1000-based dicationic acidic ionic liquid (PEG1000-DAIL). The catalyst PEG1000-DAIL could be reused seven times with excellent results. Furthermore, through this method, a highly chemoselective reaction of benzaldehyde and acetophenone with indole could be achieved.Keywords:bis(indolyl)methanes;ionic liquids;solvent-free conditions
研究领域:
有机化学
·
催化化学
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产品关联
DOI
高影响因子
Coatings
·
2017
·Vol. 7
·期 10
·159
·
IF 2.175
Shaolong Li,Changlian Xu,Wenfeng Yang,Qingru Tang
We report an efficient and green approach to synthesize a linear castor oil-based polyurethane (CPU) without using any solvent or catalyst. Diol monomers were first synthesized by the aminolysis reaction between castor oil and diamines; this was accomplished within 6 h at 130 °C. Polymerization of the diols and isocyanate was further confirmed by Fourier transform infrared (FTIR),1H-nuclear magnetic resonance (1H-NMR), and gel permeation chromatography analyses. The resultant CPUs showed a good thermal stability with an initial degradation temperature higher than 300 °C, and their mechanical and wood bonding property can be modulated by the structures of diamine. In addition, the CPUs possessed a satisfying water resistance property with the water absorption amount lower than 2%. The green conversion of castor oil to thermoplastic polyurethane affords new opportunities in bio-based industries.Keywords:castor oil;linear polyurethane;catalyst-free;solvent-free
研究领域:
材料科学
·
绿色化学
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DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 130
·107413-107420
·
IF 3.84
Qiwen Yong,Fuwei Nian,Bing Liao,Liping Huang,Lu Wang,Hao Pang
Simultaneously using sulfonic and carboxylic acid as hydrophilic chain-extending agents, a new type of solvent-free and chemical matt waterborne polyurethane resin was prepared and investigated. The chemical structure containing urethane and urea groups in this novel carboxylate/sulfonate type of waterborne polyurethane (CSWPU) resin was confirmed by FTIR, 1H and 13C NMR spectra. An obvious advantage for the environment is that, unlike the traditional synthetic method for waterborne polyurethane, the reactive system doesn't need any organic solvent to reduce the viscosity of the prepolymer in the process of prepolymerization. In addition, the gloss extinction was generated by the drying process of the resin itself, without the requirement of any matting agents. 3D-AFM images indicate that the surface of the matt CSWPU films was extremely rough and was comprised of many spherical particles with diameters in the range of 0.8–3.0 μm arranged on the films' surface. The matt CSWPU resin tended to have a relatively higher molecular weight and lower swelling ratio. Moreover, an increase of sulfonic hydrophilic chain-extending agent content or the initial molecular weight of the soft segment facilitated the improvement of thermal stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Xuehui Ge,Huanhuan Zhang,Yafei Cheng,Haiyang Shao,Lei Yuan,Senbin Shen,Guixiang Wang,Chenxiao Jiang,Xiaocheng Lin
A green anion exchange membrane for electrodialysis desalination was synthesized using a solvent-free photo-polymerization approach. Vinylbenzyl chloride (monomer), tripropylene glycol diacrylate (crosslinker), and photoinitiator were mixed and subjected to UV polymerization for 20 min to create the base membrane, followed by positive charge modification with 1-methylimidazole. This method avoids organic solvents, offering economic and environmental benefits. By adjusting the degrees of crosslinking and positive charge, precise control over the membrane's microstructure and properties was achieved. The optimized membrane showed an area resistance of 1.67 Ω cm 2 and a transport number of 0.956, demonstrating exceptional electrochemical performance. Under comparable conditions, the optimized membrane improved the NaCl removal rate by 11.47 %, increased current efficiency by 10.61 %, and reduced energy consumption by 16.75 % compared to commercial AMV membrane, highlighting its potential for scalable seawater desalination through electrodialysis.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shihao Su,Guojun Lv,Jialing Shen,Fuxin Wang,Lachgar Oussama,Yan Chen,Shengnan Xu
In the tandem synthesis of 1,2-cyclohexanediol, solvents such as acetonitrile are often added to eliminate the immiscibility of cyclohexene with water and accordingly strengthen the interphase mass transfer; however, the usage of solvents artificially increases the solvent separation procedure, enhancing the energy consumption and decreasing the economic benefits of the reaction process. Hence, the development of the solvent-free Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol is extremely appealing. In this study, β-MnO2 and Mn2O3 were prepared by calcining γ-MnO2 synthesized with the hydrothermal synthesis method and concurrently served as a colloidal emulsifier and a heterogeneous catalyst in the Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol at room temperature in the presence of the oxidant molecular oxygen and the co-oxidant isobutyraldehyde. The prepared β450-MnO2 sample revealed the best tandem catalysis performance, achieving a cyclohexene conversion of 99.4% and a 1,2-cyclohexanediol selectivity of 83.6% within 4 h of reaction, which can be ascribed to the highest Mn4+/Mn3+ ratio and the greatest concentration of oxygen vacancies as well as the most stable Pickering emulsion. At the same time, density functional theory (DFT) studies further confirmed that isobutyraldehyde and molecular oxygen could be more easily adsorbed and activated by β450-MnO2 in comparison with the other catalyst samples, benefiting its eminent catalytic epoxidation performance. In addition, a possible reaction mechanism for the β450-MnO2 catalyst catalyzing cyclohexene into 1,2-cyclohexanediol in the Pickering interfacial tandem catalytic reaction system was put forward and validated through quenching experiments as well as in situ infrared characterization. The synthesized β450-MnO2 catalyst exhibited reusability for greater than 5 cycles, and meanwhile, the Pickering interfacial tandem catalytic reaction system can be expanded to a spread of linear and cyclic alkene substrates, highlighting the superiority of the β450-MnO2 catalyst. These findings verify that the synthesized β450-MnO2 catalyst is capable of being utilized as an efficient and stable catalyst for the Pickering interfacial catalytic conversion of alkenes into 1,2-diols at room temperature.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2019
·Vol. 9
·期 7
·338
·
IF 2.061
Hangling Zhai,Chaoqun Bian,Yuxia Yu,Longfeng Zhu,Lingfeng Guo,Xiao Wang,Qinqin Yu,Jie Zhu,Xuebo Cao
The development of the sustainable synthesis of zeolites has become a very hot topic in recent years. Herein, we report a sustainable route for synthesizing all-silica SOD zeolite under solvent-free conditions. The method of solvent-free synthesis includes mixing, grinding, and heating raw solids. The all-silica SOD zeolite obtained was well characterized by multiple measurement techniques (XRD, SEM, IR, thermogravimetric-differential thermal analysis (TG-DTA), and magic angel spinning nuclear magnetic resonance (MAS NMR)). The crystallization process of all-silica SOD zeolite was also investigated in detail by XRD, SEM, UV-Raman, and MAS NMR techniques. In addition, the effects of the crystallization compositions, including the molar ratios of Na2O/SiO2and ethylene glycol/SiO2, on the synthesis of the pure all-silica SOD zeolite were investigated at different temperatures.Keywords:zeolite;sustainable route;all-silica SOD;solvent-free synthesis
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2023
·Vol. 148
·期 21
·11707-11716
·
IF 4.4
Li Xiaobei,Chen Jinxuan,Wu Lianfeng,Wang Junjun,Wang Bo,Jiang Shengling,Gu Xiaoyu,Zhang Sheng
To enhance the flame retardancy and mechanical performance of epoxy resin, a P/N-containing oligomer, polyphosphate amide (PPA) was synthesized by 1,4-phenylenediamine with dimethyl methyl phosphonate without using any organic solvent. With only 2% PPA addition in EP, the sample passed the UL-94 V-0 grade, and its limited oxygen index reached 34.0%. In the cone calorimeter test, the peak heat release rate, total heat release, and total smoke release of the EP containing 2% PPA were reduced by 23.6%, 16.0%, and 22.7% compared with that of control EP, respectively. The toughness of the pure EP was 5.0 MJ m −3 , and its impact strength and shear strength were 4.1 kJ m −2 and 8.4 MPa, respectively. With 2% PPA, the toughness, impact strength, and shear strength of EP/PPA2 were increased to 10.3 MJ m −3 , 8.8 kJ m −2 , and 14.8 MPa, respectively. This work provided a green and feasible strategy to fabricate a flame-retardant oligomer that was capable of enhancing the mechanical performance and fire resistance of the EP simultaneously.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
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2019
·Vol. 26
·期 9
·1-13
·
IF 1.53
Yang Zhihui,Zang Hu,Wu Guangfeng
A solvent-free waterborne polyurethane was synthesized via one-component crosslinking using N-[(2-amionoethyl)-amino] ethane sulphonated sodium as the post-chain extender. The effects of the N-[(2-amionoethyl)-amino] ethane sulphonated sodium and polyol content on the properties of waterborne polyurethane were investigated. The results indicate that at the optimum post-chain extender (6 mol%) and polyol (15.5 mol%) content, the waterborne polyurethane demonstrated best comprehensive properties. A clear advantage of the approach is that, in contrast with the traditional synthesis technique of waterborne polyurethane, the reaction process did not need any organic solvents to reduce the system viscosity. Also, a more natural optical appearance was obtained by the drying process of waterborne polyurethane itself. The as-developed waterborne polyurethane coating can be extensively used on the artificial leather and synthetic leather surfaces.
研究领域:
材料科学
·
高分子化学
·
绿色化学
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表面工程
·
皮革化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2025
·
IF 2.8
Jinbiao Zhao,Huimin Duan,Hao Yang,Zhichao Huang,Dongming Qi
In order to reduce the high pollution and flammability of polyurethane in high-performance automotive synthetic leather, the development of a solvent-free flame-retardant reactive polyurethane (RPU) coating material has become a research focus. However, solvent-free environments not only place higher requirements on the fluidity and processability of materials but also present significant technical challenges in achieving a balance between strength and flame retardancy. In this paper, inorganic ionic polymer particle ammonium polyphosphate (APP) was used as filler and reactive polyurethane resin as a carrier to prepare a flame-retardant modified polyurethane composite membrane with a foaming structure through a two-step method. The results showed that adding 4% APP could extend the molding time of reactive polyurethane to 550 s—an increase by about 53%—and increase its mechanical strength to 23.01 MPa. Thermal analysis verified that the cross-linking degree of reactive polyurethane resin was increased due to APP, and its thermal stability could be effectively improved. The reactive polyurethane modified with 4% APP had a residual carbon content exceeding 12% after heat treatment, and its limiting oxygen index can reach 23.7%. Additionally, the peak value of heat release rate (PHRR) was reduced by 10.7% and total heat release rate (THR) by 25.1%, enhancing the flame retardant effect. This method was of great significance to the production of polyurethane for automotive leather.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Junji Chen,Mengqin Yao,Qizhuang Zou,Peng Chen,Fei Liu,Tianxiang Zhao
An effective strategy synthesis of Rh/meso-Al 2 O 3 catalysts was demonstrated by mechanochemistry for hydrolytic dehydrogenation of ammonia borane (AB). These catalysts are characterized systematically by N 2 adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results show that the turnover frequency (TOF) and activation energy ( E a ) are 246.8 mol H2 ·mol Rh −1 ·min −1 and 47.9 kJ mol −1 for hydrolytic dehydrogenation of at 298 K catalyzed by Rh/Al 2 O 3 -CTAB-400, obviously higher than those previously reported catalysts. Furthermore, catalyst Rh/Al 2 O 3 -CTAB-400 can be recycled by simple centrifugal separation and the catalytic activity is still well maintained after five cycles. In addition, a plausible mechanism for hydrolytic dehydrogenation of AB has also been proposed. This mechanochemical synthesis method exhibits great application prospects for the preparation of heterogeneous catalysts .
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 37
·14392-14399
·
IF 8.262
HaiPeng Bai,YaPing Zheng,TianYu Wang,NingKun Peng
A magnetic, solvent-free nanofluid with a core–corona–canopy structure based on Fe3O4/polyaniline is synthesized for the first time. The solvent-free nanofluid has magnetic properties owing to the Fe3O4 core, flow ability because of the flexible chain canopy, and conductivity due to the conductive polyaniline corona and Fe3O4 core. The canopy structure possesses a nanofluid fraction of 87.7 wt%, which is high enough for it to act as the continuous phase and thus warrant fluidity. The liquid property is verified by rheological test. The percentage of crystallinity of the solvent-free nanofluid is 43%. The electric conductivity of the solvent-free nanofluid changes with temperature. The conductivity of the aqueous solution of the nanofluid can be adjusted by changing the strength or direction of the magnetic field. The fabricated solvent-free nanofluid has wide potential for application; for example, its CO2 capture capacity can reach 3.1 mmol g−1. With magnetic responsiveness, the Fe3O4/polyaniline nanofluid aqueous solution can be used in magnetic field detection.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Hongcan Sun,Shuhong Xu,Zengwei Chen,Fan Liu,Shenfei Zong,Zhuyuan Wang,Chunlei Wang
Narrow band gap emissive carbon dots (CDs), especially those with full width at half maximum (FWHM) below 40 nm, is extremely important for biological imaging application due to higher color purity and better resolution. The synthesis of narrow FWHM emissive CDs usually requires the use of specific-structured molecular precursors with a large π conjugated domain. In comparison, the most common precursors for CDs, for instance p-phenylenediamine, are usually believed unsuitable for preparing CDs with FWHM emission below 40 nm. In this work, we challenged this stereotype by using p-phenylenediamine precursor to synthesize CDs with a small FWHM of only 29 nm. Instead of using traditional solvothermal method, a facile solvent-free method was developed to synthesize CDs with the powder of p-phenylenediamine in the autoclave under a reaction temperature of 200 °C. After dispersed in solution, CDs show a red emission around 615 nm with FWHM of 29 nm and a photoluminescence quantum yield (PLQY) of 12.8%. Through experiments and theoretical calculation, we found that the FWHM emission is positive correlated to the content of amino groups on the surface of CDs. In comparison to traditional solvothermal method, the current solvent-free method can promote the synthesis of CDs with less amino groups on the surface, reducing fluorescence center types, and hence realizing smaller FWHM emission. In addition, as-prepared CDs were used for biological imaging, and realized a rapid no-wash cell imaging.
研究领域:
材料科学
·
化学
·
生物医学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）