Abstract: An electrorheological fluid e.g. for selectively coupling clutch members consists of silicone oil containing 30 volume % of dispersed polyaniline. The polyaniline is acidically oxidised aniline subsequently treated with base.

Abstract: Electrorheological fluids display swift and reversible increase in apparent viscosity under application of an electrical potential difference to the fluid, and are composed generally of electrical insulating oily medium and dielectric fine-particles dispersed therein.At the initial stage of development, electrorheological fluids are prepared by dispersing water-carrying hydrophilic particulates in an electrical insulating oily medium. However, there are such defects as a restriction on usable temperatures so as to avoid evaporation or freezing of the water, an extreme increase in the electric current flow as the temperature raises, inferior stability caused by transfer of water etc.It is an object of the persent invention is to provide nonaqueous type electrorheological fluids having improved electrorheological property.The electrorheological fluid of the present invention is a nonaqueous type electrorheological fluid which comprises organic or inorganic particulates containing not more than 1 wt.

Abstract: An electro-rheological fluid which comprises a solid particulate substance contained in a hydrophobic vehicle which is liquid at atmospheric pressure at least at temperatures below 50.degree. C. and which comprises a compound of the formula:(X).sub.n --Ar[Q--Z].sub.pwherein:Ar represents an aromatic nucleus;Q represents an oxygen or a sulphur atom, or a group of the formula CY.sub.1 Y.sub.2, SO, SO.sub.2, SiF.sub.2, --OSi(Y.sub.1 Y.sub.2)O-- in which Y.sub.1 and Y.sub.

Abstract: The invention provides a novel compound 1,1-dicyclohexyl cycloalkane derivative represented by the general formula ##STR1## in which R.sup.1 and R.sup.2 are each a hydrogen atom or lower alkyl group, R.sup.3 to R.sup.6 are each a hydrogen atom, lower alkyl group or alkylene group forming a ring structure together with either one of the others and the carbon atom in the cycloalkane ring, and m and n are each zero or a positive integer not exceeding 6 with the proviso that m+n is 4-6, such as 1,1-dicyclohexyl cyclohexane. The compound has a relatively low viscosity and high traction coefficient even at elevated temperatures so that it is useful as a constituent of a traction-drive fluid usable in a compact and light-weight traction-drive apparatus. The compound can be synthesized by subjecting a corresponding 1,1-di(hydroxyphenyl) cycloalkane compound to a hydrogenation reaction and dehydration reaction in combination in the simultaneous presence of a hydrogenation catalyst and a dehydration catalyst.

Abstract: A compliant thermally conductive, preferably dielectric, compound that enhances the power dissipation capability of high-powered electrical components such as bipolar VLSI semiconductor chips. The compound has chemically stable thermal conduction and viscosity properties; is not subject to phase separation during use and may be applied in small gaps to maximize thermal conduction. The compound preferably comprises a liquid carrier having thermal filler particles dispersed therein and a coupling agent having a functionality which is reactive with the calcined surface of the thermal filler particles, and a functionality having preferential wetting of the thermal filler particles over self-condensation. Additional additives such as fumed silica and polyisobutylene enhance the phase stability and resistance to thermo-mechanical shear force degradation of the thermally conductive compound encountered during functional usage, e.g., fluctuating power cycles.

Abstract: The electroviscous fluid is a suspension composed of a finely divided dielectric solid dispersed in an electrically nonconductive oil. The viscosity of the fluid increases swiftly and reversibly under an influence of electric field applied thereto and the fluid turns to a state of plastic or solid when the influence is sufficiently strong.The electroviscous fluid of the present invention comprises 1-60% by weight of a dispersed phase of carbonaceous particulates having average particle size of 0.01-100 micrometer, and 99-40% by weight of a continuous liquid phase of an electric insulating oil having a viscosity of 0.65-500 centistokes at room temperature.The electroviscous fluid exhibits an excellent electroviscous effect even at a high temperature with a low electric power consumption together with maintaining the improved electroviscous effect for a long period of time.

Abstract: A traction fluid comprising:(i) at least one diester or its derivative represented by the formula ##STR1## wherein A' is an ester linkage, n is an integer of 1 to 6, R.sub.1 is independently selected from hydrogen and alkyl groups containing from 1 to 8 carbon atoms, and R.sub.2 is independently selected from alkyl groups containing from 1 to 3 carbon atoms; and(ii) from 0.1 to 70 wt. % of at least one branched poly-alpha-olefin.

Abstract: A heat transfer fluid which maintains a low hydrogen permeation rate at temperatures of 350.degree.-400.degree. c. or higher and its pumpability at temperatures of -10.degree. C. or lower is provided. The fluid is especially useful in solar energy collection applications. A method of reducing fluid impurities from polyphenyls is also disclosed.

Abstract: A transparent electrorheological fluid having a fluid component, a particle component, and an activator wherein the index of refraction mismatch between the fluid component and the particle component is less than about 0.02 and wherein the conductivity of the particle component is at least about three times greater than the conductivity of the fluid component and is in the range of from about 1.times.10.sup.-5 s/m to about 1.times.10.sup.-9 s/m.

Abstract: Disclosed are electrorheological fluids which display improved stability against sedimentation, reduced current density and good electrorheological responses. In the preferred embodiment of this invention, these electrorheological fluids are prepared from monomers which are polymerized by dispersion polymerization in a low conductivity medium which also serves as the dispersion medium for the fluid.

Abstract: Antifreeze composition and composition concentrates are disclosed which comprise an alcohol, such as, for example ethylene glycol, a surface modifier, such as, for example, an organophosphate which adheres to the interior surfaces of a cooling system, and a pseudo oil, such as, for example a polypropylene glycol, which forms a film on the surface-modified, interior surfaces of the cooling system. Also disclosed are methods of making and using the composition and composition concentrates.

Abstract: An electrorheological fluid including a discrete phase of the reaction product of a polymeric or monomeric crown ether and a quaternary amine, which forms non-abrasive, low density organic fibrils, in a high dielectric strength, low dielectric constant continuous phase fluid. The crown ethers are selected from both oxygen-based and sulfur-based crown ethers.

Abstract: Cooling system cleaning solutions containing an EDTA salt, sorbitol, and a soluble nitrate salt are effective in removing scale, corrosion, and solder bloom from cooling systems without blackening aluminum, and can be formulated into concentrates having enhanced storage stability.

Abstract: Thickening agents for aqueous systems are prepared by reacting aliphatic alcohols containing 8 to 22 carbon atoms with an ethylene oxide/propylene oxide mixture, then reacting the resulting polyether with 5 to 20 moles of ethylene oxide, and reacting the resulting alkoxylation product with a diepoxide, with 0.5 to 3 moles of alkoxylation product being used in the combination reaction per mole of diepoxide. The thickening agents may be blended with low molecular weight alcohol ethoxylates, and are especially suitable for hydraulic fluids.

Abstract: A lubricating oil is disclosed, which mainly is composed of a naphthenic hydrocarbon having 19 carbon atoms comprising two cyclohexane rings which have methyl-substitution at the 1, 2 and 4 positions thereof, the two cyclohexane rings being linked by a methylene group.

Abstract: A traction fluid comprising at least one compound selected from diesters or monoesters represented by general formulas ##STR1## wherein: A is an ester linkage ##STR2## n.sub.1 and n.sub.2 are independently integers having a value of from 0 to 5 inclusive;R.sub.1 is hydrogen or a C.sub.1 -C.sub.8 alkyl; andR.sub.2 is a C.sub.1 to C.sub.3 alkyl group.

Abstract: An electrorheological material containing a carrier fluid, an anionic surfactant particle component, and an activator. The non-abrasive anionic surfactant acts as both a particle component and a surfactant and the electrorheological material is miscible with water and will not mar the surface of objects utilized in an electrorheological device.

Abstract: Gas phase and liquid phase processes are disclosed which use interconversion of CF.sub.3 CHFCl and CF.sub.2 HCF.sub.2 Cl in contact with catalyst consisting essentially of halided aluminum oxide and/or aluminum halide at elevated temperatures to increase the mole ratio of one of said compounds in a composition relative to the other. Also disclosed in use of said interconversion along with hydrogenolysis in processes for producing mixtures of CF.sub.3 CH.sub.2 F and CF.sub.2 HCF.sub.2 H from certain compositions comprising CF.sub.2 HCF.sub.2 Cl such that the mole ratio of CF.sub.3 CH.sub.2 F to CF.sub.2 HCF.sub.2 H in the product mixtures produced from said compositions may be increased or decreased.

Abstract: New chlorotrifluoroethylene telomers and process for preparing them. Chlorotrifluoroethylene is reacted, at a temperature ranging from -100.degree. to +40.degree. C., with a fluoroxy compound of formula R.sub.x --CF.sub.2 OF, wherein R.sub.x represents among others a perhalogenated alkyl radical containing from 1 to 10 carbon atoms. There are obtained telomer mixtures having, among others, the following formulae: R.sub.x --CF.sub.2 --O--(M).sub.n --F; R.sub.x --CF.sub.2 --O--(M).sub.n --O--CF.sub.2 --R.sub.x ; R.sub.x --(M).sub.n --F; R.sub.x (M).sub.n --R.sub.x ; R.sub.x --CF.sub.2 --O--(M).sub.n --R.sub.x and F--(M).sub.n --F; wherein M is CF.sub.2 --CFCL and "N" ranges from 2 to 20. Most of these telomers are new compounds.

Abstract: A medium for transmitting a motive power, comprising a hydrogenated product of an aromatic hydrocarbon compound substituted, for at least one hydrogen atom on an aromatic nucleus, with a tricyclo[5.2.1.0.sup.2,6 ]-deca-3-yl or tricyclo[5.2.1.0.sup.2,6 ]deca-4-yl group which is unsubstituted or substituted with one or more lower alkyl group.

Abstract: A lubricant comprising an oil-in-water emulsion and solid particles, in which the oil is a lubricating material and the oil droplets are stabilized by a surface coating of partially hydrophobic silica particles of a size less then 1 micrometer. This lubricant is to be used as a hydraulic fluid and as a metal-working or metal-rolling fluid.

Abstract: Disclosed are electrorheological (ER) fluids which display improved stability against sedimentation, reduced current density and good ER responses. Thes=e ER fluids are prepared from monomers which are polymerized by dispersion polymerization in a low conductivity medium which also serves as the dispersion medium for the fluid. The ER fluids are further processed by modifying the polymer particles through polymerization of a hydrophilic monomer to form a hydrophilic shell or globule around the particles followed by neutralization through addition of an organic soluble base. The resulting dispersion is then doped with water to obtain a stable ER fluid. The hydrophilic shell or globule constitutes about 15% of the particle. Water dopant is only absorbed by the hydrophilic portion of the particle and does not enter into the core of the particle. The quantity of water is significantly reduced, which in turn results in a significant reduction of the current density at any given comparative voltage.

Abstract: Disclosed are electrorheological (ER) fluids which display improved stability against sedimentation, reduced current density and good electrorheological response. These ER fluids are prepared from monomers which are polymerized by dispersion polymerization in a low conductivity medium which in most embodiments of the invention serves as the dispersion medium for the fluid. the ER fluids are further processed by modifying the polymer particles through polymerization of a hydrophilic monomer to form a hydrophilic shell or globule around the particles. The resulting dispersion is then doped with water to obtain a stable ER fluid. The hydrophilic shell or globule constitutes a minor part of the particle. Water dopant is only absorbed by the hydrophilic portion of the particle and does not enter into the core of the particle. The quantity of water is significantly reduced, which in turn results in a significant reduction of the current density at any given applied field strength.

Abstract: A quick, car-cooling composition is provided. The composition consists essentially of:about 5-15% by volume of methanol;about 20% by volume of a propellent;about 0.5% by weight of sodium benzoate;about 0.2% by volume of fragrance;about 0.2% by volume of morpholine; andabout 64.1 to 74.1% of deionized water.When sprayed in rapid, intermittent succession, the composition lowers the temperature in a hot confined space.

Abstract: In a method for manufacturing a circulating coolant system filter which includes a filter medium and a space into which a supplemental coolant additive can be placed to provide at least one beneficial property to the circulating coolant, the improvement comprising: automatically introducing the supplemental coolant additive into the space in the form of a liquid-powdered solids slurry.

Abstract: A traction fluid comprising:(i) an ester or its derivative represented by the formula: ##STR1## wherein A' is an ester linkage of --COO-- or --OOC--, n is an integer of from 1 to 14, R.sub.1 is selected from hydrogen and C.sub.1 to C.sub.8 alkyl radicals, and R.sub.2 is independently selected from hydrogen and C.sub.1 to C.sub.3 alkyl radicals; and(ii) from 0.1 to 95% by weight of a polymer selected from hydrocarbonic polymers and polyesters.

Abstract: A process for improving the coefficient of traction between at least two relatively rotatable elements in a torque transmitting relationship, and traction drive fluid composition. This composition contains the hydrogenated product of a dimer, a trimer or a polymer having a degree of polymerization of more than 3 of a cyclic monoterpenoid monomer, and exhibits excellent traction performance over a wide temperature range from low temperature to high temperature.

Abstract: Thickening agents contain polyether derivatives and low-molecular-weight alkylene glycol alkyl ethers, further common additives as required, and water as the rest, up to 100%. Mono-, di- or trialkylene glycol alkyl ethers are preferred. It is possible to prepare stock solutions with thickener concentrations of 50% and more. The thickening agents, because of their unexpectedly low viscosity, can be handled very well, and they exhibit synergistic effects during thickening, especially of aqueous systems.

Abstract: A transfer fluid for spirit fluid type duplicating systems is disclosed which comprises, generally a polyhydric alcohol, 20 to 90% by weight; and water, 10 to 80% by weight. For certain machines, a wetting agent 0 to 2% by weight, can be used with an adjustment accordingly in the amounts of the other materials.

Abstract: The use of a water-soluble hydroxyl di- or tri-carboxylic acid, generally in combination with an alkanolamine in an oil water fluid especially metal working or hydraulic fluids results in a fluid having excellent hard water compatibility, low foaming tendency in soft water and a good biostability; other additives such as emulsifiers, copper passivators and the like are generally present.

Abstract: A coolant composition for use in automotive engines is disclosed which comprises a liquid alcohol freezing depressant and a corrosion inhibitor consisting essentially of decanedioic acid, dodecanedioic acid and sodium tolyltriazole.

Abstract: A liquid polymer composition contains:(A) a liquid low molecular weight ethylene-.alpha.-olefin copolymer comprising 30 to 70 mol % of ethylene component units and 30 to 70 mol % of .alpha.-olefin component units, having a number average molecular weight (Mn) in the range of 150 to 10000, with a Q-value (weight average molecular weight/number average molecular weight) of 3 or less, and(B) A high molecular weight polymer which is in an amount of 0.05 to 100 parts by weight based on 100 parts by weight of the liquid low molecular weight polymer (A), having a number average molecular weight (Mn) of 20000 or higher, witha Q-value of 6 or less, and is soluble in the liquid low molecular weight polymer (A), which liquid polymer composition has an excellent viscosity characteristic, lubrication characteristic, and oxidation stability, without denaturation by moisture adsorption, and therefore, is suitable for use as an actuation oil.

Abstract: Charge transporting materials containing compounds having the formula (I): ##STR1## wherein R.sup.1 represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a thioalkoxy group, an aryloxy group, a methylenedioxy group, an aralkyl group, a nitro group, or an unsubstituted or substituted aryl group; R.sup.2 represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, halogen; and R.sup.3 and R.sup.4 each represent hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, halogen, a dialkylamino group, an amino group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, an aralkyl group, or an unsubstituted or substituted aryl group, k, m and n each represent an integer of 0 to 5, and l represents an integer of 0 to 4, provided that R.sup.1, R.sup.2, R.sup.3 and R.sup.4 cannot be hydrogen at the same time.

Abstract: A method for transmitting power which is characterized by the use of a traction drive fluid containing, as a base stock, a composition composed of 40 to 80 wt % of 2,4-dicyclohexyl-2-methylpentane and 20 to 60 wt % of a mixture of polycyclohexylalkane and a perhydroindane derivative, with the weight ratio of the perhydroindane derivative to the polycycloalkane being up to 0.5, and having a viscosity (at 100.degree. C.) of 5.0 to 15.0 cSt (10.sup.-2 cm.sup.2 /sec). This fluid has a high traction coefficient and a good oxidation stability.

Abstract: An improved method of inducing a change in the dynamic torque transmission of an electrorheological fluid in response to an electric field at low current comprising the steps of: (a) selecting a nonconductive liquid phase (e.g. high dielectric hydrocarbon oil); (b) dispersing in the nonconductive liquid phase a particulate phase substantially free of adsorbed water (e.g. zeolite); and (c) subjecting the resulting electrorheological fluid to an electric potential in excess of about one kilovolt at a current density of less than about one-third microamp per square inch. Such a method achieves a rate of increase of dynamic transmission of torque per unit voltage, dM/dV, in excess of about 0.034 ft-lbs.times.10.sup.-3 /kV and a ratio of dynamic transmission of torque at an electric field strength of at least 2.4 kV to the dynamic transmission of torque at zero field strength, M/Mo, of at least about 2.

Abstract: The invention relates to a process making it possible to reduce the corrosion of metals and alloys of heat exchanger circuits where aqueous heat transfer fluids are circulating and which may contain anti-freeze products.The process consists in mixing with these aqueous heat transfer fluids on the one hand from 0.05 to 5 percent by weight of one or more salts of alkali metals or of amines of dicarboxylic aliphatic acids of the formula (CH.sub.2)n(COOH).sub.2 in which n is comprised between 2 and 10 and on the other hand from 0.05 to 2.5 percent by weight of one or more polyols comprising a number of carbon atoms between 5 and 12 and a number of alcohol functions between 5 and 12 and possessing no reducing power.

Abstract: Disclosed is a transparent electrical discharge machining fluid which is provided by mixing 95-60% by weight of a mineral oil and/or a synthetic oil, 5-40% by weight of water and surface active agent in an amount of 5-40% by weight of said oil and water. This machining fluid is transparent and has a kinetic viscosity of 20 sSt or less at 40.degree. C.

Abstract: In a method for manufacturing a circulating coolant system filter which includes assembling a filter medium and a filter canister into which a supplemental coolant additive can be placed to provide at least one beneficial property to the circulating coolant, the improvement comprising: automatically introducing the supplemental coolant additive into the filter canister in the form of a liquid-powdered solids slurry.

Abstract: A stable fluid composition is provided by this invention which contains a cis-o-tercyclohexyl compound and a trans-o-tercyclohexyl compound at a weight ratio of 25:75-65:35. This composition is useful as a fluid for traction drive.

Abstract: Thermally stable polyoxyethylene polyethers prepared by oxyethylating aromatic initiators having at least two reactive hydrogens derived from amino or hydroxyl functional groups located para to each other are disclosed. These polyethers are especially suitable as solder bath oils, solder reflow oils, and heat transfer fluids for high temperature applications.

Abstract: The present invention relates to a lubricating oil composition for traction drive, which consists essentially of:(A) a base oil containing as the main component a saturated hydrocarbon or hydrocarbons having fused ring and/or nonfused ring,(B) an ethylene-.alpha.-olefin copolymer having a number-average molecular weight of 800 to 8,000, and(C) an anti-wear agent.The lubricating oil compositions of the present invention are effectively used in winter and cold districts, since they have a high coefficient of traction and show a limited change in the coefficient of traction at low temperatures.

Abstract: The present invention provided a high-density fuel oil comprising an isomerized product prepared by isomerizing an alicyclic saturated hydrocarbon represented by the following formula in the presence of an acid catalyst: ##STR1## wherein each of m and n is 0 or 1, and each of R.sup.1 to R.sup.3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, but the number of the total carbons of R.sup.1 to R.sup.3 is within the range of 1 to 3.

Abstract: Aqueous fluids are thickened with fatty acid modified polyoxyalkylene diamines. The polyoxyalkylene diamines are of the formula:H.sub.2 NCH(CH.sub.3)CH.sub.2 O(CH.sub.2 CH(R)O).sub.x CH.sub.2 CH(CH.sub.3)NH.sub.2wherein:R is methyl or hydrogen andx is a number selected to give the diamine a molecular weight of 3000 to 9000.The fatty acid is a hydrophobic mono- or dicarboxylaic acid of 12 to 36 carbon atoms. The ratio of amine equivalent: acid ranges from 1:0.5 to 1:1.The aqueous fluids optionally incorporate ethylene glycol. They are useful for water/glycol based hydraulic fluids, cosmetics and surfactants.

Abstract: An electric heat storage apparatus, such as a steam iron, hot plate, pan, etc., includes a metal body defining a hollow housing enclosing a heat storage device containing a thermally decomposable heat storage substance comprising 30-99% by weight pentaerythritol. The heat storage substance is completely confined in a fluororesin enclosure which isolates the substance from the metal body and prevents contact of ambient air therewith so that the thermal stability of the pentaerythritol is enchanced. The metal body is heated by an electric heating element to a selected temperature for storing heat in the heat storage substance. In the case of use as a cordless electric steam iron, the metal body forms the sole plate of the iron and is provided with a vaporization chamber in heat exchange relationship with the heat storage substance for the generation of steam.

Abstract: This invention provides a novel perhydrofluorene derivative which is represented by the following general formula and which is useful as a fluid for traction drive and a process for production of the derivative. ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each represents a hydrogen atom or an alkyl group of 1-4 carbon atoms, X represents (CH.sub.2).sub.p or ##STR2## wherein R.sup.4 represents a hydrogen atom or an alkyl group of 1-4 carbon atoms, p represents a real number of 2-6, q represents a real number of 1-4 and s represents 1 or 0 and k, m and n each represents a real number of 1-4.

Abstract: Aqueous fluids are thickened with epoxide modified polyoxyalkylene diamines. The polyoxyalkylene diamines are of the formula:H.sub.2 NCH(CH.sub.3)CH.sub.2 O(CH.sub.2 CH(R)O).sub.x CH.sub.2 CH(CH.sub.3)NH.sub.2wherein:R is methyl or hydrogen andx is a number selected to give the diamine a molecular weight of 3000 to 9000.The epoxide is a hydrophobic monoepoxide, diepoxide or mixture thereof.The aqueous fluid optionally incorporate ethylene glycol. They are useful for water/glycol base hydraulic fluids, cosmetics and surfactants.

Abstract: Highly branched synthetic hydrocarbon fluids produced by anionically oligomerizing selected dienes in the presence of organoalkali compounds and complexing reagents provide fluids having high traction coefficients and excellent elastohydrodynamic lubricating characteristics.

Abstract: The working fluid for traction drive use has a particularly high traction coefficient at high temperatures and the principal ingredient thereof is a decahydronaphthalene compound substituted, on either one or both of the decahydronaphthalene rings, with two or three substituent groups which may be cyclohexyl groups, cyclohexyl alkyl groups, e.g. cyclohexyl methyl, cyclohexyl ethyl, 1-methyl-1-cyclohexyl ethyl and 1-methyl-1-(methylcyclohexyl) ethyl groups, or a combination thereof. The working fluid can be a mixture of a base oil of various types and the above mentioned decahydronaphthalene compound in an amount of 5 to 250 parts by weight per 100 parts by weight of the base oil.

Abstract: An apparatus and method for changing the optical and/or physical properties of a fluid composition employ an electric field applied across the fluid for controlling the fluid properties. The fluid consists of a dielectric liquid and an electrically conductive, elongated, fibrous particulate material. The fibrous material has a length between approximately 1000 angstroms and five millimeters, a diameter less than about 700 angstroms, and an aspect ratio of length to diameter greater than about five. The particulate material is in colloidal suspension in the liquid. Generally, when the particles are dispersed in the liquid by Brownian movement forces, the fluid composition has an average separation between particles of approximately three to ten or more times the average length of the particulate material.

Abstract: A new type of ionic thickener for water-based products including functional fluids such as hydraulic fluids, cosmetic emulsions, etc. These new thickeners are prepared from polyoxyalklylene glycols, higher alkyl monoepoxides, lower alkyl monohalo lower alkyl carboxylates, and alkali metal hydroxide. These novel thickeners are generally characterized by the following formula: ##STR1## wherein R is a methylene or lower polymethylene group, R' is a higher alkyl group and R" is selected from the group consisting of oxyethylene groups and heteric or block copolymer mixtures of oxyethylene and other lower oxyalkylene groups, said copolymer containing at least 75 percent oxyethylene groups.