Sulfoxylated methyl esters as potential components of liquid formulations

Abstract

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: <phenyl C 10 , 1.3; phe...

Supercritical carbon dioxide blackcurrant seed extract as an anti-irritant additive for hand dishwashing liquids

“…The most common surfactants include alkyl aryl sulfonates, alkyl sulfonates, alkyl sulfates and alkyl ether sulfates. They are used due to their beneficial foaming properties, high washing power and easy modification of the viscosity of the product in which they are used (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). Auxiliary surfactants used in HDLs include mainly nonionic compounds (fatty alcohol ethoxylates, alkanolamides, alkyl polyglucosides) and amphoteric compounds (alkylamidopropyl betaines) (7)(8)(9)(10)(11)(12)(13).…”

“…The basic ingredients of HDLs are surfactants (1,(4)(5)(6). The compounds ensure appropriate detergent and foaming properties, and make it possible to obtain an appropriate viscosity of finished products.…”

“…The monomers interact with the skin, frequently contributing to skin irritation. Moreover, surfactants play a role in the removal of lipids from the outer skin layer, causing dryness and impairment of skin function as a protective barrier preventing the transfer of physical and chemical agents inside (4)(5)(6).…”

“…The presence of such additives typically lowers the critical micellization concentration, increases the size of micelles (hindering their penetration into the skin) and stabilizes them thermodynamically (reducing the number of micellar aggregate decompositions). The above processes entail a decrease in monomer concentration in the solution, which reduces the potential for skin irritation (6)(7)(8)(9)(10)(11)(12)(13).…”

Sulfonated methyl esters of fatty acids in aqueous solutions: Interfacial and micellar properties

“…The production of SME has been growing during the last ten years and currently it stands at more than ten percent of the LAS production. In general, sodium methyl ester sulfonates with random positioning of the SO 3 group in the alkyl chain, known as U-MES, have been synthesized [6][7][8][9][10][11]. Our study is focused on the a-sulfo fatty acid methyl esters (Fig.…”