Antifoaming Properties Research Articles

Antifoaming and deaeration properties of oils for liquid-friction bearings in rolling mills, in relation to oil composition

Antifoaming and deaeration properties of oils for liquid-friction bearings in rolling mills, in relation to oil composition

Production of PS-28 oil from West Siberian crudes

The problem of how to supply metallurgical plants with high-quality viscious oil for liquid-lubrication bearings has become serious due to the exhaustion of resources and newer severe conditions at mills. The experimental Pp-28 additive oil from medium-sulfur West Siberian crude is studied in this paper. A batch of oil of the PS-28 type from medium sulfur crudes as a base stock for the Pp-28 oil is obtained. Differences in crude source and manufacturing technology are seen to be responsible for the differences between the PS-28 experimental oil and VI-250 oil. Results obtained show that the experimental oil, in comparison with VI-250 and commercial PS-28 oil, is lower in sulfur content and carbon residue, is better in demulsifying and antifoaming properties, but is not as good in oxidation resistance. On the basis of these studies the feasibility for the production of a PS-28 type oil from West Siberian crude has been demonstrated.

Fluid for high-pressure hydraulic systems

A working fluid with a viscosity matching the requirements of the pumps, with a good viscosity/temperature and antifoaming properties, and with minimum compressibility and low leakage tendencies is needed for the higher working pressures being used in hydraulic systems. A working fluid designated MGP-80 has been developed with low leakage tendencies for the hydraulic draw systems of the diamond saws of stonecutting machines. In comparing MGP-80 working fluid with non-Soviet fluid Collag, MGP-80 was found better than Collag in dispersancy and in seizure and weld loads. Service tests of the MGP-80 fluid were such that commercial production of MGP-80 has been set up at the Drogobych experimental plant.

Antifoaming Properties of Diols. V.

Aseries ofβ-glycols such as 1, 3-alkanediols (C8C18), erythro-and threo-2, 4-alkanediols (C3C16), and erythro-and threo-3, 5-, 4, 6-, .5, 7-dodecanediols were prepared and their antifoaming pro-perties for the aqueous solution of sodium dodecylbenzenesulfonate as a foaming agent were evaluated by the Ross-Miles foam tester (JIS K 3362) and the dynamic foam meter (JIS K 2518).The results of these experiments were shown in Fig.-1Fig.-15. It was found that the aatifoam-ing properties of the β-glycols were dependent upon their molecular weights, the position and the rotational arrangements of two hydroxyl groups in the molecules.(1) The antifoaming Powers of the β-glycols increased in the order C17=C16>C18=C15=C14>C13>C12>C11=C10=C9=C8.(2) The antifoaming powers of dodecanediols were greater when two hydroxyl groups were located near the center of an alkyl chain (Fig.-18).(3) Threo isomers showed better antifoaming Properties than those of erythro isomers (Fig.-17 and Fig.-18).

Silylation of water glass. I. Solvent extraction and trimethylsilylation of silicic acid

AbstractHomogeneous trimethylsilylation of silicic acid in nonaqueous media was studied. The silylation process consisted of three steps: acidification of sodium silicate, solvent extraction. and trimethylation of silicic acid. Sodium silicate was first acidified with dilute sulfuric acid to form silicic acid: extraction followed with hydrophilic organic solvents. The Silicic acid obtained was finally allowed to react with trimethylchlorosilane to give trimethylsilylates with molecular weights of 1000–12,000. Optimum conditions for each step have been intensively sought to achieve trimethylsilylates in high yield. The trimethylsilylates exhibited excellent thermal stability and surface properties, such as water repellency and antifoaming properties, comparable to those of conventional polydimethylsiloxanes.

Antifoaming Properties of Diols. IV.

The following vicinal diols R1CH (OH) CH (OH) R2 (R1, C10H21C20H41; R2, H, CH3C9H19, R1+R2=C12H25, C14H29, C16H33, C18H37, C20H41) were prepared and their antifoaming powers were determined in order to clarify the relationship between their molecular structure and the antifoaming properties. The ethylene oxide adducts of these diols were also prepared and examined. The antifoaming powers were determined by the Ross and Miles method for the aqueous solution of sodium dodecylbenzene-sulfonate as a foaming agent. These were expressed as functions of immediate reading of foam height (foam production) and reading of foam height after 5min (foam stability), and the concentration of diols.The results of these experiments were shown in Fig.-126. It was found that the antifoaming properties of the vicinal diols were dependent upon their molecular weights and the position of two hydroxyl groups in the molecules.(1) Tetradecanediols, hexadecanediols, and octadecanediols showed excellent foam inhibiting proper-ties; the antifoaming powers of the vicinal diols increased in the order C14_≈_C16_≈_C18>C20>C22>C12>C10>C8_≈_C6.(2) The antifoaming powers of decanediols and dodecanediols were greater when the two hydroxyl groups were located near the center of an alkyl chain, but those of the symmetrical diols were not great. On the other hand, the antifoaming powers of tetradecanediols and hexadecanediols were not affected by the position of two hydroxyl groups (Fig.-26).(3) The introduction of 12 molecules of ethylene oxide to these diols improved their antifoaming powers considerably.

Foaming in submerged citric acid fermentation on beet molasses

Foam control is an important part of every fermentation technology. Chemical anti-foam agents (AFA) are surface active substances, which decrease the surface elasticity of liquids and prevent metastable foam formation. Most AFA must be mixed or dissolved in a suitable carrier substance if their antifoaming properties are to be fully utilized. The carrier seems to act as a reservoir from which the AFA is liberated.

Antifoaming Properties of Glycols. II

The authors studied on the antifoaming properties of vicinal glycols which were different in chain length and the position of neighbouring hydroxyl groups. 1, 2-Hexane-, 2, 3-hexane-, 3, 4-hexane-, 1, 2-octane-, 2, 3-octane-, 3, 4-octane-, 4, 5-octane-, 1, 2-decane-, 2, 3-decane-, 3, 4-decane-, 4, 5-decane-, 5, 6-decane-, 1, 2-dodecane-, 2, 3-dodecane-, 3, 4-dodecane-, 4, 5-dodecane-, 5, 6-dodecane-, and 6, 7-dodecanediols were derived from the corresponding olefins, which were prepared by the Wittig reactions, by the hydroxylation with hydrogen peroxide or potassium permanganate, or by the Meerwein-Ponndorf reduction of acyloins. The antifoaming power of these glycols was evaluated by the Ross and Miles method for the aqueous solutions of sodium dodecylbenzenesulforate, benzylhexadecyldimethylammonium chloride or p-nonylphenyl poly(oxyethylene) ether (n=15) as foaming agents. The results were expressed as immediate reading of foam height and reading of foam height after 5 min as a function of concentration of diols. From the results summarized in Fig.-1Fig.-16, it is evident that 5, 6-dodecanediols are superior to octanol, a commercial antifoaming agent, and comparable to silicone antifoamers. The antifoaming power of the glycols is larger when the two hydroxyl groups are located near center of the alkyl chain, but the symmetrical glycols where two hydroxyl groups centered on the alkyl chain are not so good.

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Antifoaming Properties of Glycols Derived from 1-Olefin Dimers

Antifoaming properties of new branched 1, 2 -glycols were observed for three foaming systems containing anionic, cationic or nonionic surfactants as foaming agents. The olefin dimers were prepared from C5-C12 1-olefins in the presence of triethylaluminum, and the resulting 2-alkylolefins were hydroxylated with performic acid and strong base to prepare new glycols : 2-propylheptane-1, 2-diol (10 D), 2-butyloctane-1, 2-diol (12 D), 2-hexyldecane-1, 2-diol (16 D), 2-octyldodecane-1, 2-diol (20 D) and 2-decyltetradecane-1, 2-dial (24 D). For the aqueous solution of sodium dodecylbenzenesulfonate, benzylhexadecyldimethylammonium chloride or p-nonylphenyl poly (oxyethylene) ether (n=15) as foaming agents, the antifoaming powers of these glycols were evaluated by the Ross and Miles method. The results were expressed as immediate reading of foam height and reading of foam height after 5 min as a function of concentration of glycols (Fig.-16). Glycols showed their excellent foam inhibiting properties, especially 20 D. The antifoaming powers of the new glycols decreased in the order of 20 D>24 D>12 D>10 D>16 D.

Morphine for Pulmonary Edema

To the Editor.— Except in those patients with severe chronic pulmonary disease, morphine sulfate has been a time-honored, and an unusually effective, drug. While its precise mode of action is not clear, it certainly does allay anxiety and produce venous pooling. Rotating tourniquets to all four extremities is another quick means to reduce venous return by pooling blood in the extremities. One other useful agent not mentioned in the treatment of acute pulmonary edema is intermittent positive pressure breathing (IPPB) with oxygen bubbled through 50% ethyl alcohol. The alcohol is used for its antifoaming properties; the IPPB, because it tends to lower cardiac output by decreasing venous return and subsequently decreasing left ventricular filling, which improves arterial oxygen tension.

The effect of particulate dispersing agents on the antifoaming properties of dimethicone 1000 in antiflatulent products.

Abstract The effect of finely divided silica on the antifoaming properties of polydimethylsiloxanes (dimethicone 1000) when formulated in a typical antiflatulent tablet has been examined. A dynamic froth test has been used to show that removal of extractable dimethicone by ether extraction of the tablet powder markedly reduces the antifoaming properties of the powder, despite retention of a small percentage of the polydimethylsiloxane dispersed on the surface of the silica and aluminium hydroxide gel content of the tablet. A series of static froth tests similarly demonstrate that tablet formulations from which silica is omitted also possess significant antifoaming properties.

Surface active block copolymers: I. The preparation and some surface active properties of block copolymers of tetrahydrofuran and ethylene oxide

AbstractA new type of surface active block copolymer (TE type) having the general formula HO(C2H4O)x(CH2. CH2CH2CH2O)y‐(C2H4O)zH, was obtained by addition of ethylene oxide to polyoxytetramethylene glycols with molecular weight of 1000‐3400. TE types in which the polyoxyethylene sections comprised more than 20–25% of the total weight are soluble in water, and the relation between cloud point and oxyethylene content for TE types was similar to that for propylene oxide‐ethylene oxide block copolymers (Pluronics). Some surface active properties of TE types were examined in comparison with those of Pluronics and some other surfactants. The surface tension, foaming and antifoaming properties of TE types were comparable to those of Pluronics. Although the wetting power of TE types was poor, their suspending power (for carbon black) was superior to that of Pluronics in both aqueous and nonaqeuous media. The addition of TE types to some conventional detergents enhanced significantly their detergency. TE types showed a remarkable demulsifying action, on addition to some W/O emulsions.

The use of “pluronics” administered in the drinking water as a means of bloat control in cattle

Abstract Because of their anti-foaming properties the non-ionic surface active agents Pluronic L61, Pluronic L62, and Pluronic L64 (polyoxypropylene-polyoxyethylene block polymers) have been under study for some years as a means of preventing bloat in cattle. Field experience as early as 1955 indicated that Pluronic L62 was highly effective as a drench when mixed with water, and, provided cows were given time to become accustomed to the taste, appeared to be effective when administered via the drinking water trough at the rate of approximately 0.1 oz per cow twice a day. Field application of the more readily dispersed and milder tasting Pluronic L64 in the water troughs at the same rate of application eliminated losses from bloat in the No, 1 Dairy herd of 80 to 90 cows at Ruakura over a period of seven years. The material was used throughout the period when bloat could occur. More recently, the use of an untreated herd as controls on the No. 1 Dairy Farm which was grazed by the treated herd has...

The use of 2-ethylhexanol in acute pulmonary edema.

In vitro studies indicate that 2-ethylhexanol has antifoaming properties superior to either 95 per cent or 50 per cent ethyl alcohol. Fifty per cent of 14 unselected patients suffering from severe acute pulmonary edema due to various causes showed a good response to the inhalation of 2-ethylhexanol before routine measures were instituted. In some cases relief was dramatic. There were no contraindications to its use and there were no toxic reactions. The substance is volatile, readily available and easily applied. Further studies are in progress with 2-ethylhexanol in full concentration and with oxygen under intermittent positive pressure with most encouraging results thus far.