Ester alkoxylation technology

Conventional ethyoxylation technologies, when used on fatty methyl esters, produce poor yields as well as flat ethoxymer distributions. Peaking ethoxylation catalysts have been successful in efficient conversion of methyl esters into the ethoxylates possessing peaked ethoxymer distribution. Surfactant performance of methyl ester ethoxylates was evaluated. Results generally show these to behave similarly to alcohol ethoxylates, with the exception of exhibiting a lower foam profile. This ester ethoxylation technology has been successful in ethoxylating esters of varying steric environments. Triglyceride ethoxylates have been partially saponified as well as glucaminolyzed to produce mild surfactant blends. Samuel Rosen Memorial Award Presentation, at the 90^th American Oil Chemists' Society Annual Meeting and Expo, Orlando, FL, May 1999. The author dedicates this paper to the memory of the late Professor William H. Wade of the University of Texas, Austin, TX.     

Influence of catalyst structure on direct ethoxylation of fatty methyl esters over Al-Mg composite oxide catalyst

During direct ethoxylation of fatty methyl ester over Al-Mg composite oxide catalyst, the activity was nearly proportional to the total number of active Al acidic sites on the catalyst surface per unit weight of catalyst. Lower active Al acidic site densities resulted in a narrower ethylene oxide (EO) adduct distribution of obtained ethoxylate. We developed a new catalyst with a large surface area on which many acidic sites are distributed uniformly by partially poisoning the Al acid sites of high-Al content Al-Mg composite oxide with alkali. This catalyst was used for direct ethoxylation of fatty methyl esters to obtain ethoxylated fatty methyl esters with narrow EO adduct distribution efficiently.     

脂肪酸甲酯乙氧基化物的物化性能研究

对不同烷链和不同EO加合数的脂肪酸甲酯乙氧基化物的物化性能进行了测试,并对FMEE在洗衣粉中替代AEO9进行了初步研究。结果表明,与脂肪醇乙氧基化物相比,FMEE泡沫低,水溶速度快,对油脂增溶能力强,用棕榈油甲酯乙氧基化物替代AEO9在洗衣粉中应用可改善去污性能并降低成本。     

Reduction in pluming during the spray drying of a nonionic-based heavy duty powder

The plume observed during the spray drying of a nonionic-based heavy duty powder has been attributed to volatilization/recondensation of unethoxylated alcohols and other components in the alcohol ethoxylate. These “volatile components” comprise only 24–40% of the total spray tower emissions, but they are responsible for 85–95% of the observed opacity. Therefore, the relationship between observed opacity of the plume and particulate loading is not valid for the exhaust air from a spray tower producing nonionic-based powdered detergents. Alcohol ethoxylates are not decomposed to any measurable amount in a typical spray-dryer operation. The relative pluming tendency of alcohol ethoxylates depends exclusively on their relative vapor pressure. The vapor pressure of an alcohol ethoxylate is a function of the hydrophobe composition (starting alcohol) and the degree of ethoxylation which determines the level of unethoxylated alcohols. A new generation of alcohol ethoxylates with 60% less unethoxylated alcohol for a given ethoxylation level has been introduced recently. These Novel™ alcohol ethoxylates result in drastically improved pluming characteristics.     

Effects of ethoxylate structure on surfactant properties of ethoxylated fatty methyl esters

In the presence of a surface-modified Al-Mg composite oxide catalyst, ethoxylated fatty methyl esters with different hydrophobic group structures and different chain-lengths of polyoxyethylene were synthesized from fatty methyl esters by direct ethoxylation. Each ethoxylated fatty methyl ester obtained showed a narrow ethylene oxide (EO) adduct distribution. Foaming, ability to lower surface tension, ability to lower interfacial tension, wettability, and dye solubilization were measured. Ethoxylated methyl laurate with about 60 to 70% EO content was found to be the most suitable as a base surfactant for household detergents     

Comparison of the kinetics and composition of ethoxylated methyl dodecanoate and ethoxylated dodecanol with narrow and broad distribution of homologs

Broad- and narrow-range dodecanol ethoxylates were obtained with sodium hydroxide and a proprietary calcium-based catalyst, respectively. The proprietary catalyst was also used for direct ethoxylation of methyl dodecanoate ester. Natta-Mantica distribution coefficients were calculated from the fractional content of the reaction products. A specific sequence of the distribution coefficients was observed in each case. A superior activation of the second addition step in ethoxylation of the methyl dodecanoate ester was noted. The kinetic pattern of the reaction resulted in a product distribution specifically related to the average degree of oxyethylation degree.     

Analysis of the dark-colored impurities in sulfonated fatty acid methyl ester

A fractionally distilled C₁₄−C₁₆ fatty acid methyl ester, derived from palm oil, was sulfonated with gaseous SO₃ in a falling film reactor to form an α-sulfo fatty acid methyl ester (α-SF; unbleached and unneutralized form). The included dark-colored impurities were then separated from α-SF as a diethyl ether-insoluble matter. After purification by thin-layer chromatography, the colored species were analyzed by ion-exchange chromatography, gel-permeation chromatography, and nuclear magnetic resonance spectrometry. These data suggested that the colored species were polysulfonated compounds with conjugated double bonds. Minor components in the raw fatty acid methyl ester, found by gas chromatography/mass spectrometry, were spiked into the purified methyl palmitate and then sulfonated. The unsaturated methyl ester and hydroxy ester showed the worst color results. The methyl oleate and methyl 12-hydroxystearate were then sulfonated and analyzed. Deep black products were obtained, which showed the same properties as the colored species in α-SF. It was concluded that low levels of unsaturated fatty acid methyl esters and hydroxy esters in the fatty acid methyl ester are the main causes of the coloring.     

Transesterification processes for vegetable oils: A simple control method of methyl ester content

One of the main problems in the study or industrial application of transesterification processes for vegetable oils is how to measure the methyl ester content. In this work, a quick analytical method was developed for assessing the methyl ester content of purified “fuel grade” transesterification products by applying a simple correlation with viscosity. The correlation was tested on a wide range of samples with various methyl ester contents; the results were in agreement with the values measured by gas-chromatographic analysis. In a defined range of weight fractions the correlation allows for the determination of the methyl ester content of purified transesterification products by a single viscosity measurement. This method is especially suitable for process control purposes as it determines the methyl ester content quickly and simply.     

Fatty methyl ester hydrogenation to fatty alcohol part II: Process issues

Fatty alcohols are produced by hydrogenating fatty methyl esters in slurry phase in the presence of copper chromite catalyst at temperatures of 250–300°C and hydrogen pressures of 2000–3000 psi. The fatty methyl ester, catalyst, and hydrogen are fed to the reactor cocurrently. The product slurry is passed through gas-liquid separators and then through a continuous filtration system for removal of the catalyst. A portion of the used catalyst in crude alcohol is recycled to the hydrogenator. The overall efficiency of the process depends upon the intrinsic activity, life, and filterability of the catalyst. The fatty alcohol producer therefore requires a catalyst with high activity, long life, and good separation properties. The main goal of the present laboratory investigation was to develop a superior copper chromite catalyst for the slurry-phase process. Two copper chromite catalysts, prepared by different procedures, were tested for methyl ester hydrogenolysis activity, reusability, and filtration characteristics. The reaction was carried out in a batch autoclave at 280°C and 2000–3000 psi hydrogen pressure. The reaction rates were calculated by assuming a kinetic mechanism that was first-order in methyl ester concentration. The catalyst with the narrower particle size distribution was 30% more active, filtered faster, and maintained activity for several more uses than the catalyst with the broader particle size distribution. X-ray photoelectron spectroscopy data showed higher surface copper concentrations for the former catalyst.     

Skin compatibility and ecotoxicity of ethoxylated fatty methyl ester nonionics

Ethoxylated fatty methyl esters (EFME) are nonionic surfactants obtained by direct insertion of ethylene oxide to fatty methyl esters in the presence of a composite metal oxide catalyst. Results of cumulative skin irritation testing of EFME on guinea pigs indicate that EFME are less irritating compared to ordinary alcohol ethoxylates (AE). Good skin compatibility of EFME is further illustrated by an in vitro hemolysis test and an in vitro cytotoxicity test. From the standpoint of environmental properties, EFME are readily biodegradable and are less toxic than AE. These results indicate the outstanding dermatological compatibility and good environmental compatibility of EFME.     

Methyl ester propoxylates

Insertion of propylene oxide into methyl esters is accomplished using a proprietary alkoxylation catalyst. The alkoxylation mechanism is believed to involve transesterification between the alkoxylated metal-alkoxide of the catalyst and the ester. Optimal alkoxylation conditions are discussed. The effect of inserting propylene oxide prior to ethoxylation on surface properties and foam performance is examined. Presented at the annual meeting of the American Oil Chemists' Society, Seattle, WA, May 1997.     

接枝型聚丙烯酸甲酯乙氧基化物的合成及性能研究

采用自制的酯基乙氧基化催化剂MCT-09对不同分子量的聚丙烯酸甲酯进行了直接乙氧基化,得到甲氧基封端的聚氧乙烯侧链的梳状聚丙烯酸甲酯乙氧基化物,采用红外光谱对产物进行了结构表征,并对产品的浊点、泡沫和表面张力等物化性能进行了考察。     

The effect of “peaking” the ethylene oxide distribution on the performance of alcohol ethoxylates and ether sulfates

In comparison to conventional ethoxylates, a “peaked” ethoxylate has less unethoxylated alcohol, is more soluble, and has a higher concentration of the more desired homologs. A “peaked” ethoxylate therefore has a lower odor, is easier to formulate into liquids, and can perform better in terms of detergency and wetting performance. Since “peaked” ethoxylates have less unethoxylated alcohol, less alcohol sulfate is formed during sulfation. Decreasing the content of alcohol sulfate increases the capacity to salt-thicken and can potentially improve skin mildness.     

脂肪酸甲酯乙氧基化物中未反应脂肪酸甲酯的测定

采用气相色谱法(GC)测定了不同脂肪酸甲酯乙氧基化物(MEE)中未反应的脂肪酸甲酯的质量分数。以十三酸甲酯为内标，对不同MEE进行了定性和定量分析，同时以十二酸甲酯为标准考察了回收率。实验结果表明：该法相对标准偏差在1．2％以内，回收率大于96％。由测定结果可知：GC法简便、快速、准确率高、重现性好、能准确测定不同MEE中未反应脂肪酸甲酯的质量分数，可作为MEE产品质量监控的方法，也可为MEE新产品、新配方研究与开发提供有效的参考依据。     

Metal-Catalyzed Alkene Functionalization Reactions Towards Production of Detergent and Surfactant Feedstocks

Metal complexes have been used as catalysts in alkene transformation reactions to produce alcohols, esters, and organic acids as potential raw materials for the manufacture of detergents, perfumes, and other fine chemicals. Herein, we report the use of palladium(II) and ruthenium complexes as efficient catalyst precursors for the methoxycarbonylation, hydrogenolysis, and ethoxylation reactions of higher alkenes. The palladium catalysts showed high chemoselectivity (>98 %) and regioselectivities of about 40 % towards the formation of esters and branched isomers, respectively. Subsequent hydrogenolysis of the esters to the corresponding alcohols was achieved using ruthenium catalysts. Reactions of the esters and alcohols with ethylene oxide using calcinated aluminum oxide catalysts produced the corresponding alcohol and methyl ester ethoxylates, respectively. The identity of the phosphine derivatives, catalyst loading, reaction time, temperature, and pressure were found to influence the catalytic activity and regioselectivity of the complexes.     

Organic reactions in emulsions—Preparation of glycerol and polyglycerol esters of fatty acids by transesterification reaction

Monoglycerol and polyglycerol esters of fatty acids have been prepared in an emulsion medium of polyglycerol in esters of fatty acids. Transesterification between glycerol or polyglycerols and methyl esters of fatty acids is made at relatively low temperatures (95–150 C) in the presence of alkaline catalyst and anionic or nonionic emulsifiers. The reaction system consists of two immiscible phases transformed into a “milky” (macro) or transparent (micro) emulsion throughout the heating process. The product obtained using this technology is not a highly substituted ester since the transesterification reaction is selective. The type and the amount of emulsifier have to be carefully selected. Unsuitable emulsifiers which will not stabilize the emulsion are ineffective in enlarging the contact between the reactants; therefore, the conversion of the reactants is very poor. With suitable emulsifiers, the conversions and the yields improved due to a better contact between reactants.     

Chemoenzymatic epoxidation of unsaturated fatty acid esters and plant oils

In the presence of an immobilized lipase fromCandida antacrtica (Novozym 435^R) fatty acids are converted to peroxy acids by the reaction with hydrogen peroxide. In a similar reaction, fatty acid esters are perhydrolyzed to peroxy acids. Unsaturated fatty acid esters subsequently epoxidize themselves, and in this way epoxidized plant oils can be prepared with good yields (rapeseed oil 91%, sunflower oil 88%, linseed oil 80%). The hydrolysis of the plant oil to mono- and diglycerides can be suppressed by the addition of a small amount of free fatty acids. Rapeseed oil methyl ester can also be epoxidized; the conversion of C=C-bonds is 95%, and the composition of the epoxy fatty acid methyl esters corresponds to the composition of the unsaturated methyl esters in the substrate. Based partly on a lecture at the 86th AOCS Annual Meeting & Expo, San Antonio, Texas, May 7–11, 1995.     

Fatty alcohols

“Fatty” or higher alcohols are mostly C₁₁ to C₂₀ monohydric compounds. In probably no other homologous aliphatic series is the current balance between natural and synthetic products so vividly evident. Natural sources, such as plant or animal esters (waxes), can be made to yield straight chain (normal) alcohols with a terminal (primary) hydroxyl, along with varying degrees of unsaturation. In the past, socalled fatty alcohols were prepared commercially by three general processes from fatty acids or methyl esters, occasionally triglycerides. Fatty acids add hydrogen in the carboxyl group to form fatty alcohols when treated with hydrogen under high pressure and suitable metal catalysts. By a similar reaction, fatty alcohols are prepared by the hydrogenation of glycerides or methyl esters. Fatty alcohols are also prepared by the sodium reduction of esters of fatty acids in a lower molecular weight alcohol. The sodium reduction method was ordinarily too expensive; it was displaced early by the other methods; finally most unsaturated alcohols made by this route were largely replaced. Methyl ester reduction continues to provide perhaps 20% of the saturated fatty alcohols, and selective hydrogenation with the use of special catalysts such as copper or cadmium oxides was developed for the production of oleyl alcohol. Synthetic or petroleum technology for long chain alcohols include the Ziegler process, useful for straight chain, even-numbered saturated products. A second is the carbonylation and reduction of olefins affording medium or highly branched chain alcohols. Paraffin oxidation affords mixed primary alcohols. Fatty alcohols undergo the usual reactions of alcohols. They may be reacted with ethylene oxide to yield a series of polymeric polyoxyethylene alcohols or with acetylene under pressure to yield vinyl ethers or with vinyl acetate to give vinyl ethers.     

Direct ethoxylation of fatty methyl ester over Al-Mg composite oxide catalyst

For the purpose of estimating the reaction mechanism of the direct ethoxylation of a fatty ester in the presence of an Al-Mg composite oxide catalyst, a labeled fatty methyl ester C₁₁H₂₃CO¹⁸OCH₃ containing ¹⁸O isotope was synthesized and directly ethoxylated. The product was evaluated by gas chromatography-mass spectrometry (GC-MS). The GC-MS spectra showed that the ¹⁸O isotope label was present only in the methoxy group at the molecular end of the ethoxylated fatty methyl ester. This supports the reaction mechanism of coordination anionic polymerization where the bond between the acyl and methoxy groups of the fatty methyl ester molecule was broken, caused by the bifunctional effect of the acid-base active sites; an intermediate chemisorption species was formed; and then ethylene oxide was addition-polymerized sequentially, in parallel.     

Reduction of fatty ester Δ2-isoxazoline heterocycles. Preparation of fatty esters containing the β-hydroxy ketone moietyheterocycles. Preparation of fatty esters containing the β-hydroxy ketone moiety

Fatty ester compounds containing the β-hydroxy ketone moiety were prepared in good yields from their corresponding fatty Δ²-isoxazoline heterocyclic precursors by a reductive hydrogenolysis-hydrolysis procedure using Raney nickel as catalyst. By this methodology, C-17, C-18, and C-19 straight-chain fatty methyl esters containing the 10-hydroxy 12-keto moieties were prepared in 73, 83, and 92%, respectively, from their corresponding isoxazoline fatty ester compounds. Two other 10-hydroxy 12-keto C-12 and C-14 fatty ester compounds were prepared in 84 and 92% yield, respectively. The C-12 β-hydroxy ketone contains a phenyl ring at C-12, whereas the C-14 β-hydroxy ketone compound has two methyl substituents at C-13. GC-MS using electron impact ionization was used to determine the hydroxyl and ketone positions after conversion of the hydroxyl group into its corresponding trimethylsilyl ether. The precursor fatty ester Δ²-isoxazolines used in this study are readily available in one step from a 1,3-dipolar cycloaddition reaction between nitrile oxides and methyl 10-undecenoate. This overall two-step sequence, 1,3-dipolar cycloaddition followed by reductive ring opening, represent a convenient method to construct fatty ester compounds in good yields containing the β-hydroxy ketone functionality, an outcome not easily accessible by other methods.