2-Ethylhexyl laurate, as an exemplary longerchain aliphatic ester, was subjected to direct ethoxylation. The synthesis was described and the obtained products were analyzed qualitatively by means of the mass spectrometry and chromatographic methods. Solubility of the obtained ethoxylates was studied by determination of their cloud points in selected model solutions. It was shown that longer-chain aliphatic esters are feasible as raw materials for ethoxylation in the presence of an appropriate catalyst. They undergo effective and selective reaction with ethylene oxide without formation of excessive amounts of by-products. The obtained products exhibit typical properties of ethoxylate-type nonionic surfactants. Their solubility in water and butyldiglycol solution was relatively lower compared to their methyl ester equivalents.Paper no. S1226 in JSD 4, 167-173 (April 2001).KEY WORDS: Aliphatic esters, ethoxylation, 2-ethylhexyl laurate.The common definition of ethoxylation requires the presence of a labile hydrogen group in the substrate subjected to the reaction, according to Equation (1):where R denotes hydrocarbon chain and X means an intermediate group, such as -O-, -N-, or -S-. However, it was found recently that the reaction can also be performed efficiently with fatty acid methyl ester as the substrate (2,3). Since then several catalysts that allow efficient performance of the reaction have been reported (4-6). Ethoxylation of fatty methyl esters was also carried out using the conventional alkaline catalysts (7), although the rate of ethylene oxide (EO) addition was slow and the product distribution obtained was broad. It was proven that during ethoxylation of fatty methyl ester, EO was inserted selectively between the carbonyl carbon and the methoxy group (8).RCOOCH 3 + nCH 2 CH 2 O → RCO(OCH 2 CH 2 ) n OCH 3[2] Substrate Adduct Ethoxylation product Propoxylation of fatty acid methyl esters was also reported in the literature (9). Earlier studies described the impact of methyl ester chain length, degree of unsaturation, and EO content on the physical properties and performance of methyl ester ethoxylates (7,10,11). However, in considering the more recently described effective ethoxylation of the ester bond, a wide spectrum of additional raw materials appears to be relevant for the manufacture of nonionic surfactants. Some of them are already available commercially. They include longer aliphatic esters applied as ecological organic solvents, lubricants, modern bio-fuel additives, or other auxiliary agents. The aim of this work was to present the results from direct ethoxylation of 2-ethylhexyl laurate as an exemplary longer-chain aliphatic ester subjected to the reaction and to study the solubility of the products obtained in water and in 2-(2-butoxyethoxy)ethanol (butyldiglycol: BDG) solution. EXPERIMENTAL PROCEDURESThe following materials were used: oxirane (Mazovian Petrochemical Works, P / lock, Poland); 2-ethylhexyl laurate, marked as Polcet L (CHEMCO Production and Trade Company, Sobowidz, Poland); and ...
A series of segmented polyurethanes (PUs) based on 4,4Ј-diphenylmethane diisocyanate and 1,6-hexamethylenediisocyanate; polyoxypropylenediol (POPD); and low-molecular chain extenders, 1,2-propanediol or 3-chloro-1,2-propanediol was obtained by solution polymerization and characterized by GPC and microscopic methods. Spherical aggregates with diameter of about 200 nm, arranged in a quasi-linear mode, were observed by SEM technique; further investigations by the TEM method revealed hard-segment domains of longitudinal shape, with length of about 5-10 nm, showing some features of the arrangement along a "director" axis. The process of thermal decomposition was monitored by thermogravimetric analysis in both dynamic and isothermal mode; to gain a deeper look into the mechanism of decomposition, kinetic analysis was performed. First, isoconversional methods showed a multistep decomposition route, as the value of (apparent) energy of activation changes from about 150 kJ/mol in the first step up to about 350 kJ/mol in the third step, which corresponds to the energy of dissociation of COC bonds and leads to a char (carbonaceous) residue. Further calculations by means of the linear regression method revealed that kinetic model functions describing the degradation process of PU that does not contain chlorine were Bna 3 An 3 Fn, whereby for chlorine-containing polyurethanes the CnB 3 An 3 An model was applied as best fit. Volatile products were investigated by pyrolysis-gas chromatography/mass spectrometry method at 770°C; the low molecular weight decomposition products, which were identified, indicate that the depolymerization process, yielding mainly diols and isocyanates through breakage of urethane bonds, prevailed during the thermal treatment under pyrolytic conditions. Finally, the mechanism of thermal degradation of modified polyurethanes with lowered flammability was proposed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3214 -3224, 2004
Ethoxylation of simple alcohols such as methanol, ethanol and butanol in the presence of tripropylamine, in addition to the main reaction products, results in by‐products from tripropylamine and ethylene oxide. This side‐reaction consumes tripropylamine, forming dipropylamine ethoxylates and alcohol ethoxylates. These compounds remain in the product and influence the commercial properties of alcohol oxyethylates.
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