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31.
The reaction of dimedone with various aromatic aldehydes produces 2,2'-arylmethylene bis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) in excellent yields. The reactions occur in water as solvent at room temperature and avoiding the addition of any catalyst. The workup procedure is very simple and the products do not required further purification. 相似文献
32.
An emerging approach: In the ionothermal synthesis of transition-metal-oxide clusters an ionic liquid acts as a solvent, structure-directing agent, and charge-compensating species. The method may open new convenient routes for the synthesis of polyoxometalate-based materials. 相似文献
33.
The maleic acid‐castor oil monoester (MACO) was synthesized and was used as monomer to synthesize a new potentially environmentally friendly copolymer of styrene and MACO (poly‐St/MACO) by suspension polymerization. Under the appropriate conditions, the poly‐St/MACO with yield of 81%, number average molecular weight of 44100 g/mol, and molecular weight distribution of 1.5 could be obtained. The chemical structures of the MACO and resulting copolymer were confirmed by Mass Spectrometry Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy H[1]. The results of thermogravimetric analysis and biodegradation test showed the poly‐St/MACO can be used as a new potentially environmentally friendly material with excellent thermal stability. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
34.
用环境友好催化剂H-β沸石制备紫罗兰酮 总被引:1,自引:1,他引:0
用环境友好催化剂H-β沸石催化假性紫罗兰酮环化制备紫罗兰酮。考察了催化剂的用量、反应温度和时间对反应的影响,并测定了假性紫罗兰酮环化反应的速率常数和活化能(36.4kJ/mol).H-β沸石能被回收、再生和重复使用,且与用新鲜H-β沸石时几乎有相同的紫罗兰酮产率。 相似文献
35.
Jingjing Zhang Congcong Wang Huwei Xing Qian Fu Chenxi Niu Lingbin Lu 《Molecules (Basel, Switzerland)》2022,27(21)
The frequent occurrence of crude oil spills and the indiscriminate discharge of oily wastewater have caused serious environmental pollution. The existing separation methods have some defects and are not suitable for complex oil–water emulsions. Therefore, the efficient separation of complex oil–water emulsions has been of great interest to researchers. Asymmetric wettable Janus materials, which can efficiently separate complex oil–water emulsions, have attracted widespread attention. This comprehensive review systematically summarizes the research progress of asymmetric wettable Janus materials for oil–water separation in the last decade, and introduces, in detail, the preparation methods of them. Specifically, the latest research results of two-dimensional Janus materials, three-dimensional Janus materials, smart responsive Janus materials, and environmentally friendly Janus materials for oil–water separation are elaborated. Finally, ongoing challenges and outlook for the future research of asymmetric wettable Janus materials are presented. 相似文献
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37.
A novel medium-length fluorinated diols and poly(L-lactide) (PLLA) were synthesized via Michael addition reaction and ring-opening polymerization, respectively. Subsequently, Synthetic medium-length fluorinated diols and PLLA were combined to prepare new polyurethane composites with degradability and low surface energy. The compositional analysis and structural characterization of synthetic materials were characterized by using fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectra (1HNMR). Thermogravimetric analysis(TGA) indicated that the introduction of medium-length fluorinated diols improved the thermal stability of the polyurethane. The biodegradation and low surface energy of the polyurethane were investigated by static hydrolysis experiment and water contact angle test. It was found that the degradation rate of the polyurethane increased as measurement time went on when the PLLA content was under 40%, and the water contact angle increased from 71.12° to 108.24° with the increase of fluorine content, which indicated that the degradable and low surface energy polyurethane has a potential as a coating material for a marine antifouling coating application. 相似文献
38.
We have systematically studied the reactions of acetalization and found that high reaction efficiency can be achieved using cheap and readily available organic Eosin Y as catalyst. The reaction proceeds smoothly under house bulbs and shows excellent functional group tolerance. The substrates of the reaction system are compatible with aromatic aldehydes, aliphatic aldehydes, aromatic ketones, and cyclic ketones with high yields. 相似文献
39.
《Journal of heterocyclic chemistry》2017,54(2):1598-1603
Hexamethylenetetramine catalyzes synthesis of new polyfunctionalized 4H‐pyrans by the reaction of aromatic aldehyde, malononitrile, and β‐keto esters via one‐pot three‐component procedure in water medium. Addition of reactants was performed by two methods led to achieve similar results. Using hexamethylenetetramine in catalytic amount not only represents the economic face of the reaction but also due to the use of water, a green and safe reaction condition is organized. Thus, the current strategy provides the benefits of high productivity, convenient operation, and environmental friendliness. The structure of all products were proved by elemental analysis, IR, 1H NMR, and 13C NMR spectroscopy. 相似文献
40.
A new, fast, solvent-free and efficient method is provided to prepare thioformamides by reacting isocyanides derivatives, carbon disulfide and benzylamine under microwave irradiation. 相似文献