A-Glycol monoethers

In the presence of BF-, etherate, 1 isomerizes to y-alkoxyallyltins, which react with aryl aldehydes to form mainly sy/t-a-glycol monoethers (equation II). How-... 

Natural Products. Many natural products, eg, sugars, starches, and cellulose, contain hydroxyl groups that react with propylene oxide. Base-cataly2ed reactions yield propylene glycol monoethers and poly(propylene glycol) ethers (61—64). Reaction with fatty acids results ia a mixture of mono- and diesters (65). Cellulose fibers, eg, cotton (qv), have been treated with propylene oxide (66—68). 

In this paper we apply basic solution thermodynamics to both the adsorption of single surfactants and the competitive adsorption of two surfactants on a latex surface. The surfactant system chosen in this model study is sodium dodecyl sulfate (SDS) and nonylphenol deca (oxyethylene glycol) monoether (NP-EO o) These two surfactants have very different erne s, i.e. the balance between their hydrophobic and hydrophilic properties are very different while both are still highly soluble in water. 

The nonionic surfactant, nonylphenol deca(oxyethylene glycol) monoether, NP-EO10, supplied by Berol Kemi AB, Stenungsund, Sweden, was of technical grade and used without further purification. The main impurity is free polyethylene oxide. Analysis of the sample gave a polyethylene oxide content of = 3% (4). Note, that polyethylene oxide adsorbs on polystyrene latexes ( ), but a monolayer is reached at solution concentrations that are 10 times the concentration required to obtain a monolayer coverage with NP-EO q. The free polyethylene oxide, therefore, is expected to have negligible influence on the adsorption measurements. 

In a subsequent reaction with the solvent, PO produces small amounts of propylene glycol or glycol monoethers. The rate of formation of PO from propylene, H202, and TS-1 in methanol at 313 K is shown in Fig. 22. The selectivity to PO is 85%, but it can be improved by silanization of the catalyst, which reduces the hydrolytic activity, or by addition of small amounts of sodium acetate to the reaction mixture. With these modifications, at 97%... 

Fig. 2.3. Plots of log CMC (in mole fraction units) versus nc, the number of carbon atoms in the alkyl chain. (Temperature in general 25 °C). a. Alkyl hexaoxyethylene glycol monoethers (Data from Ref.113)). b. Alkyl trimethylammonium bromides in 0.5 M NaBr (Data from Refs.28, 114)).

Decarbonylotion of a-alkoxy acid chlorides. The reaction of an a-alkoxy acid chloride with a ketone mediated by Sml2 results in a 1,2-glycol monoether and liberation of CO. The necessary molar ratios are 2 1 4, acid chloride/ketone/ Sml2.4... 

Since their commercial introduction in 1926, glycol ethers have become valuable as industrial solvents and chemical intermediates. Because glycol monoethers contain a -OCH2CH2OH group, they resemble a combination of ether and ethyl alcohol in solvent properties. The most common... 

The reaction of isoprene monoxide with a range of alcohol pronucleophiles in the presence of the ligand (3 mol%), Pd2dba3.CHCl3 (1 mol%) and triethylboron (1 mol%) gave the glycol monoethers in excellent yield and enantiomeric excess. The use of p-methoxybenzyl alcohol and 3-nonyl-3,4-epoxybut-1-ene afforded an intermediate that was converted into (—)-malyngolide (eq 8). ... 

Of these products the main one was the carbinol LXII. A similar oxide intermediate explains the formation of benzylmethylcarbinol from a-bromopropiophenone. In addition to the ethers corresponding to these carbinols, there was also obtained the monoether of a glycol. This may have been formed from the intermediate oxide (LVI) by the addition of isopropyl alcohol to the oxide ring, or by diipct reaction of the bromo-hydrin (LV) with aluminum isopropoxide. Curiously enough, when the reduction was carried out at 33°, a-bromoisobutyrophenone gave a bromohydrocarbon as the main product. This was shown to be LXIII accompanied by some of its allylic isomer (LXIV). 

Woo the temperature dependence of pitch for chiral nematic polymers does not seem to follow any particular pattern. It is believed that as temperature is increased, specific interactions, e.g., hydrogen bonding, whether inter- or intramolecular or polymer-solvent interactions are destroyed. The polymer chains become more flexible and the side groups more easily relaxed, thereby changing the physical properties of the chiral nematic structure. Similarly, an increase in concentration leads to a decrease in pitch for most lyotropic cellulosic liquid crystals with the exception of cellulose tricarbanilate (CTC) in ethyl methyl ketone, 2-penta-none, or tiiethylene glycol monoether and the chlorophenyl urethane derivative in diethylene glycol monoether. ... 

Therefore AH° may be calculated from the surface tension-log C plots at various temperatures. Unfortunately, the errors in locating the cmc (which in many cases is not a sharp point) leads to a large error in the value of AH°. A more accurate and direct method of obtaining AH° is microcalorimetry. As an illustration, the thermodynamic parameters, AG°, AH° and TAS° for octylhexaoxyethylene glycol monoether (CgE ) are given in Table 3.2. 

The dodecyl penta(oxyethylene glycol) monoether was synthesized from Aldrich dodecyl alcohol (98%) by adding 5 mol of ethylene oxide per mol of alcohol this reaction produces the typical distribution in degree of ethoxylation. The synthesis of nonylphenyl methacrylate was by a straightforward reaction of methacryloyl chloride (Aldrich) and nonylphenol (Kodak). Proton NMR spectroscopy just before use indicated 77% double bonds the rest were alkyl hydrogens, presumably because of polymerization. 

KOJ Kojima, C., Yoshimura, K., Harada, A., Sakaitishi, Y., and Kono, K., Temperature-sensitive hyperbranched poly(glycidol)s with oligo(ethylene glycol) monoethers, J. Polym. Sci. Part A Polym. Chem., 48, 4047, 2010. 

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