ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Wenwen Zhang,Boyu Zheng,Xiaoxiao Jin,Heyong Cheng,Jinhua Liu
Epoxy compounds are an important class of organic intermediates that are generally used to synthesize many important compounds and natural products. Herein, we carried out two-phase epoxidation of α,β-unsaturated olefins in microdroplets without any catalysts, where all the yield measurements were made upon microdroplet collection using high performance liquid chromatography. The epoxidation reaction can only take place under thermal irradiation both in microdroplets and in bulk phase, and an optimal yield was obtained in microdroplets at a reaction temperature of 35 °C. The epoxidation yield in microdroplets (85%) was superior over that in bulk phase (13%). In addition, the microdroplet epoxidation also produced configuration-selective epoxy compounds (only E-epoxides from the corresponding E-olefins and only Z-epoxides from the corresponding Z-olefins) compared to more byproducts (E-/Z-olefins and E-/Z-epoxides obtained from either E-olefins or Z-olefins) in bulk phase. It was attributed to E/Z configuration conversion under light irradiation in bulk phase, whereas such conversion was trivial in microdroplets. We also found that the epoxidation yields of trans-chalcones into their corresponding E-epoxides were apparently higher than cis-chalcones.
研究领域:
有机化学
·
绿色化学
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2014
·Vol. 41
·期 8
·5809-5819
·
IF 1.54
Zhao Bing,Jiang Lili,Liu Zhuo,Deng Qigang,Wang Liyan,Song Bo,Gao Yan
A microwave-assisted, convenient, efficient, and catalyst-free procedure is described for the synthesis of 1,3-diphenyl-3-(pyridin-2-ylamino)propan-1-one derivatives by Michael addition of 2-aminopyridine to the chalcones. Short reaction times, simple reaction, easy of product isolation, high yields, and clean work-up are the advantages of this method.
研究领域:
有机化学
·
药物化学
·
合成方法学
·
绿色化学
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Yanlin Liu,Binbo Wang,Songqi Ma,Tao Yu,Xiwei Xu,Qiong Li,Sheng Wang,Yingying Han,Zhen Yu,Jin Zhu
Carbon fiber reinforced composites (CFRCs) are a kind of most potential materials due to the high strength-to-weight ratio, excellent fatigue and corrosion resistance . However, the vast majority of CFRCs prepared from carbon fiber and thermosetting matrices are difficult to be recycled and depend on limited fossil resources . Here, for the first time, we reported fully bio-based catalyst-free epoxy vitrimers for CFRCs. The epoxy vitrimers exhibited excellent malleability and could be reprocessed by compression molding . Outstanding degradability was also achieved, which enabled multiple recovery of CF from their CFRCs without damage. In addition, CFRCs regenerated from multiple recovered CF exhibited insignificant differences from the original CFRCs. This work will provide an effective method for the sound development of CFRCs from both economic and environmental aspects.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HETEROCYCLIC CHEMISTRY
·
2022
·Vol. 59
·期 9
·1561-1572
·
IF 2.035
Ling Jiang,Si-Yu Yan,Jing-Wen Dong,Li-Dan Ye,Yue Cheng,Xiao-He Chu
A series of polysubstituted pyrroles were rapidly synthesized in moderate to good yields via catalyst-free one-pot three-component reaction of 1,3-dicarbonyl compounds with primary amines and nitrostyrenes by using liquid-assisted grinding. This protocol provides several advantages over the conventional chemical synthesis, such as simple work-up procedure, wide substrate scope, short reaction time, and environmental friendliness. Structures of polysubstituted pyrroles were confirmed by 1 H NMR, 13 C NMR, and ESI-MS studies.
研究领域:
有机化学
·
药物化学
·
绿色化学
·
合成方法学
·
杂环化学
✓ 已验证
DOI
高影响因子
Sustainable Materials and Technologies
·
2024
·
IF 8.6
Yue-Rong Zhang,Song Gu,Yu-Zhong Wang,Li Chen
An intrinsically flame-retardant epoxy vitrimer with multi-reprocessability was successfully constructed and applied to carbon fiber-reinforced composites with the aim of promoting more economical and sustainable development in the field of fire-safe applications. In this work, a catalyst-free flame-retardant epoxy vitrimer constructed by synthesizing phosphaphenanthrene-derived anhydride (DPI) and using triethanolamine (TEOA) as a multifunctional transesterification modifier was used to solve the two major problems of flame retardancy and recyclability at once. The epoxy resin and its composites exhibit excellent flame retardancy, mechanical properties, and rapid repairability, yet the ability to pass the UL-94 V-0 rating even after reprocessing the epoxy resin five times; while the value of the peak heat release rate (PHRR) and the total heat release (THR) reduced by 58% and 35%, showing great suppression on heat release. In addition, the resin can be completely degraded under mild conditions, enabling 100% recycling of the carbon fibers.
研究领域:
材料科学
·
可持续发展
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Yang Chen,Chang Zhang,Ning Wang,Martin Jensen,Xianfeng Li,Xingxiang Zhang
Self-assembled ultralong Si 3 N 4 /SiO 2 nanowires (SiNNWs) with core-shell structure are prepared by air jet-spinning followed by high-temperature calcination employing low-cost fumed nano silica and industrial polyacrylonitrile as raw materials. Without using metal catalysts or reductive atmosphere, Si 3 N 4 /SiO 2 nanowires are generated through autocatalysis and self-assembly. The ultralong SiNNWs are uniform and continuous throughout the entire length with a 3–4 nm amorphous SiO 2 shell layer on surface of the Si 3 N 4 . The diameter of the SiNNWs is about 80–200 nm with the length being at centimeter level and the main component of the SiNNWs is the standard hexagonal cell of α-Si 3 N 4 . Moreover, the photoluminescence spectrum of SiNNWs exhibits an intense blue-green light emission at room temperature. The self-assembly mechanism of the SiNNWs is discussed.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2025
·
IF 4.3
Chenru Tian,Ganggang Zhang,Jun Liu,Liqun Zhang
The conventional curing methods pose a significant environmental threat due to the use of toxic vulcanizing agents, the release of irritating volatile organic compounds, and the difficulties in recycling end-of-life rubber products. This work demonstrates a catalyst-free, facile, and eco-friendly crosslinking strategy based on the reaction between epoxy-functionalized ethylene-propylene-diene monomer (EEPDM) and dicarboxylic acids. The EEPDM was synthesized via a reusable reaction-controlled phase-transfer catalyst. Then, EEPDM could be effectively crosslinked by dicarboxylic acids without additional additives. The increased acidity of dicarboxylic acids could be conducive to improving the crosslinking rate. Moreover, the curing mechanism and the nature of the crosslinks were investigated, which is crucial for the recyclability of rubbers. The dicarboxylic acid-cured EEPDM exhibited undesirable side reactions, the extent of which showed a positive correlation with the acidity of carboxylic groups. This phenomenon could be primarily attributed to acid-catalyzed self-polymerization via epoxide ring-opening mechanisms, which would be detrimental to the reprocessability. Due to the formation of thermally stable ether linkages, the crosslinked EEPDM exhibited enhanced thermal-oxidative aging behavior. Hence, we envision that this catalyst-free, high-efficiency crosslinking strategy may offer a promising bridge between sustainable modification and high-performance for epoxy-functionalized rubbers, holding potential application in eco-friendly, low-odor automotive sealing strips.
研究领域:
高分子科学
·
材料工程
·
绿色化学
·
橡胶技术
·
化学合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 27
·12934-12940
·
IF 3.925
Hansen Yang,Zhimiao Wang,Hualiang An,Qiusheng Yang,Wei Xue,Fang Li,Yanji Wang
Theobromine is an important pharmaceutical intermediate and food additive. We have developed a green method for theobromine synthesis, namely catalyst-free methylation of 3-methylxanthine with dimethyl carbonate (DMC). The effects of various solvents on the reaction were investigated; H2O was found to be the most appropriate solvent. The bond energies of C–O in DMC and N–H in 3-methylxanthine were calculated at the M06-2x/6-311G(d,p) level, and the role of the solvent was examined theoretically. The use of H2O as the solvent and the effects of DMC hydrolysis on the reaction were investigated. The results show that DMC hydrolysis was, to some extent, beneficial to theobromine synthesis. The reaction conditions were optimized. When the molar ratio of DMC to 3-methylxanthine was 11 : 1 and the 3-methylxanthine dosage was 0.1 g per mL-H2O, reaction at 160 °C for 9 h gave a 3-methylxanthine conversion of 89.9% with 98.2% theobromine selectivity.
研究领域:
药物化学
·
绿色化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2020
·Vol. 36
·期 5
·816-820
·
IF 1.063
Chu Ning,Xu Shuping,Xu Weiqing
Two different kinds of configurations of 1,4-bis[2-(4-pyridyl)ethenyl]-benzene( trans -bpeb and cis -bpeb) were achieved, and a bpeb dimer was synthesized in dimethyl sulfoxide(DMSO). Compared with the previous work that synthesized the bpeb dimer or polymer in crystal with a template agent needed, the reaction occurred in a solution phase in the present method. A hand-held ultraviolet lamp(365 nm) with the power of 12 W and the Watt density of 0.35 mW/cm 2 can realize the photodimerization of bpeb, instead of the high-power mercury lamp in most previous studies. Unlike other 2+2 cycloaddition in liquid state using catalysts even noble metals, no catalysts were required here, which is cost-saving. Only the trans -pbeb can start the cycloaddition and the formation of the close J-aggregations of trans -pbeb in DMSO is a precondition for explaining the 2+2 photodimerization. The productivity for the 2+2 cycloaddition product was achieved as 55.6%.
研究领域:
有机化学
·
光化学
·
超分子化学
·
材料化学
·
合成方法学
✓ 已验证
DOI
高影响因子
Nature Photonics
·
2025
·
IF 32.9
Zhai Jianxin,Wang Ruo-Ya,Chen Xiao,Zhou Baowen,Xia Zhanghui,Wu Haihong,Xue Teng,Jia Shuaiqiang,Chen Chunjun,Jing Lihong,He Mingyuan,Han Buxing
The photon-mediated conversion of CH 4 and CO 2 represents a green and sustainable route for producing transportation fuels and chemicals. Here we report an innovative, catalyst-free strategy for the conversion, by light, of CH 4 and CO 2 into CO/H 2 and C 2 H 6 . High-energy photons with a wavelength of 185 nm were found to initiate the reaction, and the additional use of photons with different energies at longer wavelengths further improved the reaction efficiency. In particular, the combination of 185-nm and 200–1,100-nm photons enabled CO, H 2 and C 2 H 6 production rates of 3.1 mmol m −3 h −1 , 1.93 mmol m −3 h −1 and 2.53 mmol m −3 h −1 , respectively. Moderate addition of H 2 O was found to aid the reaction considerably. Moreover, a total gas conversion of 1.51% (24 h) was achieved in experiments simulating an oxygen-free environment. This work opens up a promising route for producing fuels and chemicals using CH 4 and CO 2 without the use of any catalysts, under ambient conditions.
研究领域:
能源化学
·
环境科学
·
光化学
·
可持续能源
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2019
·Vol. 13
·期 7
·1900063
·
IF 3.729
Di Wu,Jiao Shi,Xiaoming Zheng,Jinxin Liu,Weidong Dou,Yongli Gao,Xiaoming Yuan,Fangping Ouyang,Han Huang
One-dimensional (1D) atomically thin crystals have attracted considerable interest due to their unique properties and potential applications. Herein, the chemical vapor deposition (CVD) growth of molybdenum disulfide (MoS 2 ) nanoribbons on sapphire(0001) supported monolayer MoS 2 flakes without catalysts as well as the characterizations by means of Raman and photoluminescence (PL) spectroscopy, optical microscopy (OM), atomic force microscopy (AFM), and scanning transmission electron microscopy (STEM). The Raman and PL results is reported, as well as OM images reveal that such MoS 2 nanoribbons grow on monolayer MoS 2 flakes. STEM and selected area electron diffraction (SAED) results reveal that they are grown along the 〈 10 1 ¯ 0 〉 direction with atomically sharp edges. Controlled experiments show that the deficiency of sulfur vapor at the beginning of growth induced 1D MoO x S 2− x crystals as precursors. The subsequent sulfurization changes them into MoS 2 nanoribbons. These findings provide a facile approach to MoS 2 nanoribbons and enrich the horizon of the preparation of nanostructured transition metal dichalcogenides.
研究领域:
材料科学
·
纳米科技
·
表面科学
·
凝聚态物理
·
低维材料
✓ 已验证
DOI
高影响因子
ACS Applied Polymer Materials
·
2023
·
IF 5
Xiaobo Xu,Xiaozhen Ma,Xiaolin Wang,Jin Zhu,Jinggang Wang,Ning Yan,Jing Chen
Using sustainable biomass feedstock to prepare biobased chemical products is attracting increasing attention. Betulin is a natural cyclic aliphatic diol that can be extracted in large quantities from the bark of birch trees. In this study, a series of bio-based polyurethane (PU) elastomers with excellent mechanical properties, solvent resistance, and thermal stability were synthesized under catalyst-free conditions using betulin and castor oil (CO) as the bio-based polyols. The chemical structure and properties of the bio-based PU elastomers were systematically investigated according to the effect of the hydroxyl ratio between betulin and CO. Due to the presence of abundant hydrogen bonds and rigid ring planes in the PU structure, and a higher cross-link density, the obtained PU elastomers had excellent mechanical properties. They achieved a maximum tensile strength of 31.6 MPa with the tensile strain reaching more than 200% and were able to withstand 1 × 105 times their weight. The thermal decomposition temperature of the betulin-derived PUs was over 300 °C. This study showcased a strategy to synthesize sustainable high-performance PU materials with a high biomass content (>75%).
研究领域:
材料科学
·
化学工程
·
可持续性
·
聚合物化学
✓ 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）