scholarly journals The stability of emulsions in the presence of additives

2002 ◽  
Vol 67 (1) ◽  
pp. 31-40 ◽  
Author(s):  
S. Gasic ◽  
Bratislav Jovanovic ◽  
S. Jovanovic
Keyword(s):  
Ethylene Oxide ◽  
Ethylene Glycol ◽  
Homologous Series ◽  
Opposite Effect ◽  
General Trend ◽  
Inversion Point ◽  
The Stability ◽  
Index Value ◽  
Phenol Index

The influence of different additives on the effectiveHLBvalues of non-ionic emulsifiers was studied by the method of the determination of the phenol index values and by the determination of the emulsion inversion point in the system with xylene as the oil phase. Ethanol, glycerol and ethylene glycol were investigated as additives. The method of the determination of the phenol index value was applied on two homologous series of non-ionic emulsifiers: nonylphenolpolyglycolethers with 10, 15, 23 and 30 moles of bound ethylene oxide and polyglycolethers of fatty alcohols (C16?C18) with 15, 20 and 23 moles of bound ethylene oxide. The additives were applied in the concentration of 5, 10, 15 and 20 %. The results showed that ethanol and ethylene glycol increased the phenol index value. The influence of ethanol was more pronounced. On the contrary, glycerol reduces the phenol index value. There were small differences in the influence of these additives on certain members of both homologous series, but the general trend is presented here. The influence of the same additives on the values of the emulsion inversion point was investigated in the system with xylene and nonylphenolpolyglycolethers with 10 moles of bound ethylene oxide. Ethanol and ethylene glycol were applied in the concentrations of 1, 5, 10 and 15 % and glycerol in 5,7.5,10 and 15 %. The results showed that ethanol and ethylene glycol reduce the emulsion inversion points, while glycerol increases them. On the basis of these investigations it can be concluded that ethanol and ethylene glycol could contribute to an increase in the stability of emulsions, glycerol has the opposite effect. The results of both applied methods are in accordance.

Rapid Gas Chromatographic Determination of Ethylene Oxide, Ethylene Chlorohydrin, and Ethylene Glycol Residues in Rubber Catheters

1985 ◽  
Vol 68 (3) ◽  
pp. 506-508 ◽  
Author(s):  
Richard J Muzeni
Keyword(s):  
Ethylene Oxide ◽  
Ethylene Glycol ◽  
Linear Response ◽  
Chromatographic Determination ◽  
Flame Ionization Detection ◽  
Ethylene Chlorohydrin ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Isothermal Gas

Abstract Isothermal gas chromatography with flame ionization detection was used to determine residual ethylene oxide (EtO), ethylene chlorohydrin, and ethylene glycol in soft rubber catheters that had been sterilized with EtO. Catheter samples were extracted by shaking with carbon disulflde, and the extract was analyzed on a 3% Carbowax 20M on 80- 100 mesh Chromosorb 101 column, using nitrogen as the carrier gas. Ten replicate injections of a mixed standards solution gave coefficients of variation of 1.91, 1.23, and 4.74% for EtO, ethylene chlorohydrin, and ethylene glycol, respectively. A linear response was obtained with concentrations ranging from 1.0 to 7.9 μg EtO, 14.0 to 88.0 μg ethylene chlorohydrin, and 31.0 to 98.5 μg ethylene glycol. The proposed method detected as little as 0.5, 5.0, and 16.5 ng EtO, ethylene chlorohydrin, and ethylene glycol, respectively.

Hydrogenolysis of glucose and fructose in glycol solutions over CuO-MgO-ZrO2 catalyst

2020 ◽  
pp. 48-55
Author(s):  
M.E. Sharanda ◽  
◽  
E.A. Bondarenko ◽  
Keyword(s):  
Ethylene Glycol ◽  
Propylene Glycol ◽  
Flow Reactor ◽  
General Trend ◽  
Raw Materials ◽  
Reaction Products ◽  
Renewable Raw Materials ◽  
High Partial Pressure ◽  
Zro2 Catalyst ◽  
Phase Process

Ethylene glycol and propylene glycol are important representatives of polyols. On an industrial scale, they are obtained from petrochemical raw materials. Within a decade, significant efforts were made for the producing of polyols from biologically renewable raw materials - carbohydrates. The general trend for carbohydrate hydrogenolysis includes application of liquid-phase process with the use of modified metal-oxide catalysts, at 120-120 ° C and pressure of 3MPa or above. So high pressure is used for the reason to increase hydrogen solubility, and also due to the high partial pressure of low boiling solvents. We supposed that usage of high boiling solvents could allow hydrogenolysis to be performed at the lower pressure. Ethylene glycol and propylene glycol are of particular interest as such kind of solvent since they are both the main products of glucose hydrogenolysis. In this work, the process of hydrogenolysis of glucose and fructose over Cu / MgO-ZrO2 catalyst have been studied at temperature range of 160-200 °C and a pressure of 0.1-0.3 MPa in a flow reactor. The solvents were simultaneously the target products of the reaction - ethylene glycol and / or propylene glycol. Gas chromatography and 13C NMR were used for the reaction products identification. It was found that the solubility of glucose in propylene glycol is 21 % by weight, and in ethylene glycol 62% by weight. It was pointed out that the process of hydrogenolysis can take place at a pressure close to atmospheric. Under these conditions, the conversion of hexoses reaches 96-100 %. The reaction products are preferably propylene glycol and ethylene glycol. The total selectivity for C3-2 polyols is 90-94 %, that is higher than in the hydrogenolysis of glucose in aqueous solution.

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