Esterification synthesis of ethyl oleate catalyzed by Brønsted acid–surfactant-combined ionic liquid

ABSTRACT 3-(N,N-dimethyldodecylammonium) propanesulfonic acid hydrogen sulfate ([SB3-12][HSO4]), a Brønsted acidic-surfactant-combined ionic liquid, was successfully prepared from cheap materials and applied to catalyze the esterification synthesis of ethyl oleate using oleic acid and ethanol as precursors. The produced condition of oleic acid ethyl ester was optimized including the amount of catalyst, reaction time, molar ratio and content of water. Under optimal condition (ethanol to oleic acid molar ratio, 3:1; amount of the catalyst, 5 wt% (based on the mass of oleic acid); reaction time, 3 h; reaction temperature, 78°C; and content of water, 0.4 wt%), the conversion of oleic acid was over 97%. Due to the reverse micelles formed by [SB3-12][HSO4], the micro-reactor not only promoted the esterification toward the desired side of the ester, but also avoided the hydrolysis of ester. Moreover, the [SB3-12][HSO4] could be reused by a simple decantation separating process and noticeable loss of catalytic activity was not observed even after being recycled for five cycles. The green system offers several advantages, such as excellent yield, efficient catalytic activity, free-solvent and simple operational procedure. GRAPHICAL ABSTRACT

[1]  F. D. Souza,et al.  The chameleon effect in zwitterionic micelles: Binding of anions and cations and use as nanoparticle stabilizing agents , 2013 .

[2]  T. Igarashi,et al.  Dehydrative esterification of carboxylic acids with alcohols catalyzed by diarylammonium p-dodecylbenzenesulfonates in water , 2012 .

[3]  K. Manabe,et al.  Dehydration reactions in water. Surfactant-type Brønsted acid-catalyzed direct esterification of carboxylic acids with alcohols in an emulsion system. , 2001, Journal of the American Chemical Society.

[4]  Liangchun Li,et al.  Chiral surfactant-type catalyst for asymmetric reduction of aliphatic ketones in water. , 2012, Journal of the American Chemical Society.

[5]  David C. Forbes,et al.  Novel Brønsted acidic ionic liquids and their use as dual solvent-catalysts. , 2002, Journal of the American Chemical Society.

[6]  Wumanjiang Eli,et al.  Solvent-free esterification catalyzed by surfactant-combined catalysts at room temperature , 2007 .

[7]  Shuj Kobayashi,et al.  Dehydration reactions in water. Brønsted Acid-surfactant-combined catalyst for ester, ether, thioether, and dithioacetal formation in water. , 2002, Journal of the American Chemical Society.

[8]  M. Ghiaci,et al.  Esterification of fatty acids by new ionic liquids as acid catalysts , 2014 .

[9]  Y. Liu,et al.  Preparation of biodiesel from waste oils catalyzed by a Brønsted acidic ionic liquid. , 2009, Bioresource technology.

[10]  Fei Meng,et al.  Surfactant-free Ionic Liquid Microemulsions of N,N-dimethylformamide, 1-butyl-3-methylimidazolium hexafluorophosphate, and toluene , 2015 .

[11]  Wumanjiang Eli,et al.  Study on the Polarity of bmimPF6/Tween80/toluene Microemulsion Characterized by UV-Visible Spectroscopy , 2009 .

[12]  S. B. Halligudi,et al.  Bronsted acidic ionic liquids : A green, efficient and reusable catalyst system and reaction medium for Fischer esterification , 2005 .

[13]  Liangzhi Li,et al.  A Brønsted acidic ionic liquid as an efficient and environmentally benign catalyst for biodiesel synthesis from free fatty acids and alcohols. , 2009, Bioresource technology.

[14]  Jian-hua Cheng,et al.  Acidic ionic liquid-catalyzed esterification of oleic acid for biodiesel synthesis , 2014 .

[15]  Lei Wang,et al.  Biodiesel Production by Esterification of Oleic Acid over Brønsted Acidic Ionic Liquid Supported onto Fe-Incorporated SBA-15 , 2012 .

[16]  Lu Li,et al.  Synthesis of plasticizer ester using acid-functionalized ionic liquid as catalyst. , 2008, Journal of hazardous materials.

[17]  Xiaorui Gao,et al.  Biodiesel synthesis from the esterification of free fatty acids and alcohol catalyzed by long-chain Brønsted acid ionic liquid , 2013 .

[18]  Z. A. Schelly,et al.  Investigation of the microenvironment in triton X-100 reverse micelles in cyclohexane, using methyl orange as a probe , 1992 .

[19]  B. S. Souza,et al.  Synthesis of a new zwitterionic surfactant containing an imidazolium ring. Evaluating the chameleon-like behavior of zwitterionic micelles. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[20]  Shaohua Zhang,et al.  A cyclic voltammetric technique for the detection of micro-regions of bmimPF6/Tween 20/H2O microemulsions and their performance characterization by UV-Vis spectroscopy , 2006 .

[21]  Yunfeng Qiu,et al.  Efficient, stable, and reusable Lewis acid–surfactant-combined catalyst: One-pot Biginelli and solvent-free esterification reactions , 2014 .

[22]  M. Harmer,et al.  Solid acid catalysis using ion-exchange resins , 2001 .

[23]  Fang Dong,et al.  Functionalized ionic liquid as the recyclable catalyst for Mannich-type reaction in aqueous media , 2009 .

[24]  Aiko Hasegawa,et al.  Polystyrene-Bound Tetrafluorophenylbis(triflyl)methane as an Organic-Solvent-Swellable and Strong Brønsted Acid Catalyst. , 2001, Angewandte Chemie.

[25]  Gaoyong Zhang,et al.  A Brønsted acidic ionic liquid as an efficient and reusable catalyst system for esterification , 2004 .

[26]  M. Borissova,et al.  Micellar electrophoresis using ionic liquids. , 2008, Journal of chromatography. A.

[27]  C. F. Oliveira,et al.  Esterification of oleic acid with ethanol by 12-tungstophosphoric acid supported on zirconia , 2010 .

[28]  A. Fontana,et al.  Structural modifications of ionic liquid surfactants for improving the water dispersibility of carbon nanotubes: an experimental and theoretical study. , 2011, Physical chemistry chemical physics : PCCP.

[29]  Jungbae Kim,et al.  Highly stabilized lipase in polyaniline nanofibers for surfactant-mediated esterification of ibuprofen. , 2014, Langmuir : the ACS journal of surfaces and colloids.

[30]  Alexandre F. Santos,et al.  Solid-Acid-Catalyzed Esterification of Oleic Acid Assisted by Microwave Heating , 2010 .

[31]  Guozhen Gong,et al.  Highly efficient procedure for the synthesis of biodiesel from soybean oil using chloroaluminate ionic liquid as catalyst , 2009 .

[32]  M. L. Ferreira,et al.  Solvent-free ethyl oleate synthesis mediated by lipase from Candida antarctica B adsorbed on polypropylene powder , 2005 .

[33]  M. V. Martínez-Huerta,et al.  Synthesis of biodiesel from Nigella sativa seed oil using surfactant-Brønsted acidic-combined ionic liquid as catalyst , 2014 .