Synthesis, characterization, and surface properties of sulfoxylated methyl esters

Cohen, L.; Vilches, Francisco Javier Trujillo

doi:10.1007/s11743-998-0033-3

Cited by 18 publications

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References 5 publications

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“…This product was obtained in our laboratory according to a modification of the methodology described (1). Basically, the modification consists of the use of hot water instead of a mixture of water and ethanol for the separation of the acid phase at the reactor outlet.…”

Section: Methodsmentioning

confidence: 99%

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Sulfoxylated methyl esters as potential components of liquid formulations

Cohen

Soto

Luna

2001

J Surfact & Detergents

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Sulfoxylated methyl esters (Φ-MES) are obtained via sulfoxidation of fatty acid methyl esters with SO 2 , O 2 , and ultraviolet light of appropriate wavelength. These products may be used as co-surfactants with linear alkylbenzene sulfonate and alkyl ether sulfate, either in heavy-duty or in hand dishwashing liquids. Standard hand dishwashing formulations based on Φ-MESC 16 are presented and discussed with regard to solubility, viscosity, performance, and skin compatibility. The experimental results obtained indicate that the above-mentioned products can be regarded as potential components for liquid formulations.Paper no. S1222 in JSD 4, 147-150 (April 2001).KEY WORDS: Φ-MES, LAS, AES, hand dishwashing liquids.In previous papers (1,2), the synthesis, characterization, and performance of sulfoxylated methyl esters (Φ-MES) were described. According to these results (2), Φ-MES showed: good solubility, very low viscosity of water solutions even at high concentration, and low sensitivity to water hardness. Furthermore, these are natural products and are then expected to have (i) excellent biodegradability and (ii) good skin compatibility. As a result, these products can be viewed as new anionic surfactants with potential application in formulations for hand dishwashing liquids or for heavy-duty liquids. The aim of the present work is to study their behavior in hand dishwashing formulations, where Φ-MES has been combined with the leading types of surfactants used in the world today: linear alkylbenzene sulfonate (LAS), alkyl ether sulfate (AES), and alcohol ethoxylate (AE). DISHWASHING LIQUID FORMULATIONSA competitive dishwashing liquid has to meet certain basic requirements, such as: good water solubility, low viscosity even at high concentrations, mildness to skin, effective fat and oil dissolution, and high and stable foam. Almost all European dishwashing liquid formulations are a mixture of LAS, AES, and other minor components and solvents (most frequently water). In order to study how the former formulations would behave if one or both of the major components (LAS or AES) were replaced partially by Φ-MES, the following ternary formulations (Table 1) were tested with regard to solubility, viscosity, stability to water hardness, skin compatibility, foaming, and hand dishwashing performance. MATERIALSΦ-MESC 16 sodium salt (where C 16 = carbon chain length). This product was obtained in our laboratory according to a modification of the methodology described (1). Basically, the modification consists of the use of hot water instead of a mixture of water and ethanol for the separation of the acid phase at the reactor outlet. In addition, the sodium sulfonate has been extracted with n-butanol. The detailed analytical procedure has been published previously (3). The selection of the methyl ester carbon range was done according to the performance previously obtained (2).LAS sodium salt. A commercial sodium sulfonate mixture derived from a linear alkylbenzene (LAB) with the following wt% composition:

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Section: Methodsmentioning

confidence: 99%

“…In previous papers (1,2), the synthesis, characterization, and performance of sulfoxylated methyl esters (Φ-MES) were described. According to these results (2), Φ-MES showed: good solubility, very low viscosity of water solutions even at high concentration, and low sensitivity to water hardness.…”

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confidence: 99%

Sulfoxylated methyl esters as potential components of liquid formulations

Cohen

Soto

Luna

2001

J Surfact & Detergents

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“…Therefore, in the present investigation a C 12 fatty acid methyl ester was sulfoxidized with SO 2 , O 2 , and ultraviolet light of 257.3 nm wavelength as described previously (2). The sulfonic acid was further extracted from the reactor outlet product with n-hexane as described previously (3), and a different derivatization technique was applied using potassium iodide and trifluoroacetic anhydride (TFAA) (4).…”

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Analysis of sulfoxylated methyl esters (Φ-MES): Sulfonic acid composition and isomer identification

et al. 2003

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Derivatization of a C 12 Φ-methyl ester sulfonic acid by using iodide-trifluoroacetic anhydride in dimethylformamide in a one-step reaction yielded derivatized sulfonic thiotrifluoroacetates. The latter have been analyzed by gas chromatography-mass spectrometry (MS) and liquid chromatography-MS techniques so that, for the first time, the acid composition and the mono sulfonic acid isomer distribution are shown.Paper no. S1298 in JSD 6, 151-154 (April 2003).KEY WORDS: C 12 Φ-sulfoxylated methyl ester, composition, derivatization, isomer identification.In our previous work (1), a C 16 Φ-methyl ester sulfonic acid (Φ-MES C 16 ) sample was derivatized by methylation with trimethylorthoacetate in excess to give the dimethylester sulfonate. Different analytical techniques were used to analyze the sample, such as gas chromatography (GC)-mass spectrometry (MS), 1 H nuclear magnetic resonance (NMR), liquid secondary ionization mass spectrometry (LSIMS), and tandem MS. The main conclusions drawn from that investigation were as follows: (i) The SO 3 group was positioned randomly. (ii) GC-MS showed the presence of at least 11 isomers that could not be characterized. (iii) 1 H NMR indicated that the major species present contained one CHSO 3 and one CH 2 CO 2 group, confirmed the presence of different isomers, and suggested the presence of polysulfonates. (iv) LSIMS and LSIMS/MS confirmed the presence of CH 3 (CH 2 ) m CH(SO 3 Me)(CH 2 ) n CH 2 CO 2 Me (M.W. = 364 where m + n = 12); very little α or β substitution; and the presence of polysulfonated species of the forms CH 3 (CH 2 ) m CH(SO 3 Me)(CH 2 ) n CH(SO 3 Me)(CH 2 ) p CH 2 CO 2 Me and CH 3 (CH 2 ) m C(SO 3 Me) 2 (CH 2 ) n CH 2 CO 2 Me. Probably as a result of the instability of the derived methyl esters, the research (1) could not be completed and the identification of each isomer remained a goal to be reached.Therefore, in the present investigation a C 12 fatty acid methyl ester was sulfoxidized with SO 2 , O 2 , and ultraviolet light of 257.3 nm wavelength as described previously (2). The sulfonic acid was further extracted from the reactor outlet product with n-hexane as described previously (3), and a different derivatization technique was applied using potassium iodide and trifluoroacetic anhydride (TFAA) (4).Although the random position hypothesis was confirmed for Φ-MES C 16 (1), the present work describes the sulfonic acid composition and identifies each positional isomer for the first time by means of GC-MS and liquid chromatography (LC)-MS. EXPERIMENTAL PROCEDURESDerivatization of Φ-MES C 12 . According to a method developed by Li and Lin (5) and applied by Pratesi et al. (4), a sulfonic acid methyl ester sample, obtained through sulfoxidation (2) and further hexane extraction (3), was derivatized by the TFAA/potassium iodide method (4), and the derivatives were analyzed by GC-MS and LC-MS [electrospray ionization (ESI) source].In this procedure (4), the sulfonic group is first reduced to an alkyl-thiol group. Then the trifluoroacetic acid group is added to ...

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“…The operating conditions for the synthesis of Φ-MES and the analytical network for its separation and purification have been documented (1). Nevertheless, further work has been performed to improve the separation and extraction processes.…”

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confidence: 99%

“…It is therefore necessary first to separate the nonreacted methyl ester from the reaction products in order to recover the former for further synthesis. In previous work, the separation procedure proposed has some weaknesses (1). The separation of Φ-MES from the nonreacted methyl ester with a mixture of water/ethanol yields, an organic phase and an acidic phase.…”

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confidence: 99%

Separation and extraction of Φ‐methyl ester sulfoxylates: New features

Cohen

Soto

Luna

2001

J Surfact & Detergents

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This paper deals with the separation and purification of Φ-methyl ester sulfoxylates obtained through the sulfoxidation process. Two new steps are implemented during separation of the final product from the nonreacted reagent: (i) hot water is used instead of water/ethanol mixture, and (ii) n-butanol is used as the extractive phase after neutralization instead of ethanol, leading to a product with more than 75% active ingredient. A significant improvement in the separation and purification steps has been obtained. The new procedure allows a complete material balance of the main products formed during sulfoxidation of fatty acid methyl esters and thus can lead to study of the reaction conditions, which can improve both conversion and selectivity.Paper no. S1195 in JSD 4, 73-74 (January 2001).KEY WORDS: Extraction, Φ-MES, separation.Φ-Ester sulfoxylates (Φ-MES) are new anionic surfactants obtained through sulfoxidation of fatty acid methyl esters with SO 2 , O 2 , and ultraviolet light of appropriate wavelength. The operating conditions for the synthesis of Φ-MES and the analytical network for its separation and purification have been documented (1). Nevertheless, further work has been performed to improve the separation and extraction processes. After completion of the sulfoxidation reaction, the reactor product contains mainly mono-and polysulfonic acids; some fatty acids, most probably resulting from fatty methyl ester hydrolysis; some sulfuric acid; and all the nonreacted fatty acid methyl ester since the reaction conversion is close to 30% w/w. It is therefore necessary first to separate the nonreacted methyl ester from the reaction products in order to recover the former for further synthesis. In previous work, the separation procedure proposed has some weaknesses (1). The separation of Φ-MES from the nonreacted methyl ester with a mixture of water/ethanol yields, an organic phase and an acidic phase. However, by this procedure, the separation is incomplete, leaving some impurities in both the acidic and the organic phases. Furthermore, some fatty acid remains in the acid phase, leading to a final product with a significant soap content.After the separation is carried out, the desired product has to be separated from the unwanted materials such as fatty acid, sulfuric acid and other nonidentified impurities. For purification, the previous method (1) uses ethanol as the extractive phase after neutralization of the acidic phase and dryness. This procedure is time-consuming (several days), and many of the impurities soluble in ethanol are extracted as well, making it impossible to obtain a final Φ-MES product with more than 40% active ingredient. All of these problems have been overcome with the methodology presented herein. MATERIALS AND METHODSSeparation procedure. The analytical network shown in Scheme 1 depicts two new methods for the separation of the reacted from the nonreacted products, which are mainly Φ-MES sulfonic acid (mono-and polysulfonic acids), fatty acid and nonreacted methyl ester: the hot wate...

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Synthesis, characterization, and surface properties of sulfoxylated methyl esters

Cited by 18 publications

References 5 publications

Sulfoxylated methyl esters as potential components of liquid formulations

Sulfoxylated methyl esters as potential components of liquid formulations

Analysis of sulfoxylated methyl esters (Φ-MES): Sulfonic acid composition and isomer identification

Separation and extraction of Φ‐methyl ester sulfoxylates: New features

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