Polyphenyl Ether Research Articles

10. Further developments with single structure vapour pumping groups

A pumping group with an additional liquid nitrogen cooled baffle or plate primarily to cryopump water vapour arising from the system is described. Reasons for using this variant are given and its performance compared with the simpler pumping group. The performance for air and other gases when charged with polyphenyl ether fluid is contrasted to those obtained with perfluoro polyether fluids with particular reference to their pumping stability for air, hydrogen and helium. Mass spectra of the residual atmosphere when using both polyphenyl ether and perfluoro polyether in both the watercooled and liquid nitrogen trapped versions are given. Comparative spectra of the watercooled version and a turbomolecular pump is also included. The choice of a fluid for specific applications is discussed taking into account its performance in the pump, chemical stability and other relevant factors. Applications in which this type of pumping group has been used successfully are discussed.

Volatile liquid hydrocarbons in the surface coastal waters of the Gulf of Mexico

Abstract A sampling and analysis procedure has been developed to determine quantitatively volatile liquid C 6 C 14 hydrocarbons, the most immediately toxic components of petroleum hydrocarbons, at the ng/l level characteristically found in marine waters. The method of analysis involves dynamic headspace sampling; continuous stripping of volatile hydrocarbons from heated seawater by an ultrapure inert gas, and trapping of volatile components on a solid polyphenyl ether adsorbent, Tenax-GC. The trapped components are subsequently desorbed from the Tenax-GC by heating to 250°C, with cryogenic (liquid nitrogen) trapping of the volatile hydrocarbons on a SE-30 pre-column. After the cryogenic trapping, the pre-column is then heated rapidly which ‘injects’ the trapped components onto a non-polar GC column for separation. The stripping system is uniquely designed in that the stripping of the volatiles is done in the sample bottle itself. Components are identified by means of GC-MS analyses and GC retention times. The reproducibility based on replicates is ±12%. The use of conventional oceanographic samplers is found to be unsuitable for liquid hydrocarbon sampling at the ng/l level. Distributions of liquid hydrocarbons were determined in coastal surface waters of the Gulf of Mexico. Total volatile n-alkane concentrations range from 7 ng/l to 50 ng/l, whereas total volatile aromatics (benzene, toluene, ethylbenzene and xylenes) range from 20 ng/l to 450 ng/l. At most sample stations, 80–90% of the total liquid hydrocarbons in surface water is aromatic. The contribution in seawater of these volatile hydrocarbons to the total solvent-extractable hydrocarbon budget is a few percent at most. A direct correlation exists between liquid hydrocarbon concentrations and C 1 C 5 hydrocarbon concentrations. Surface-water samples which show high liquid hydrocarbon concentrations (500 ng/l) are also extremely high in methane and ethane relative to open-ocean levels. Samples which are lowest in liquid hydrocarbons (30 ng/l) have concentrations of methane and ethane close to baseline or open-ocean concentrations.

Separation of phenois on a polyphenyl ether with six rings. II

Separation of phenois on a polyphenyl ether with six rings. II

Purification of polyphenyl ethers by vacuum distillation

Purification of polyphenyl ethers by vacuum distillation

Gas chromatographic separation of phenols on a polyphenyl ether with six rings. I

The separation of C 7–C 15 monohydric alkylphenols, C 9 and C 10 indanols, C 10 and C 11 naphthols, and 5,6,7,8-tetrahydro-1-naphthol on a column packed with 5% (w/w) of a polyphenyl ether with six rings on Chromaton N AW HMDS has been studied. The retention indices for the column temperatures used (140 and 160°) were determined. It was found, that a relationship between retention index and number of C atoms can find only limited use in the identification of individual phenols.

Analysis of Mobility, Volatility, Morphology, Physical States, and Oxidation Stability of Selected Contact Lubricants

The increasingly strenuous and variable thermal environments in which static gold-plated contacts must operate has generated a need for expanded information on the physical properties of traditional and new lubricant materials. This work investigated the mobilities, volatilities, oxidation stabilities, morphologies, and physical states of microcrystalline waxes, synthesized hydrocarbons, polyphenyl ether, di-2-ethylhexylsebacate, and polyethylene glycol over a wide temperature range. The mobilities of the microcrystalline waxes, high viscosity synthesized hydrocarbons, polyphenyl ether, and polyethylene glycol were all very low. The relative volatilities were: di-2-ethylhexylsebacate > low viscosity synthesized hydrocarbon > polyethylene glycol > polyphenyl ether > microcrystalline wax> high viscosity synthesized hydrocarbon. Oxidation tests indicated that the microcrystalline waxes and synthesized hydrocarbons were mildly sensitive to oxidation. Morphologies of thin films, determined up to 150°C with scanning electron microscope, were variable. The microcrystalline waxes and high viscosity synthesized hydrocarbons existed as generally uniform films with some clustering. The di-2-ethylhexylsebacate produced a very uniform film, and the polyphenyl ether distributed itself in a beaded nonwetting manner.

Lubricants for Separable Connectors

About two dozen lubricating fluids were tested for use on electrical contacts on card edge or pin-and-socket connectors. The lubricants selected for screening represented a cross section of thewide variety of natural and synthetic materials available on the market. Among them were polyphenyl ethers, natural and synthetic hydrocarbons, several types of esters, polygiycols, some fluorinated materials, a few silicones, and some proprietary formulations. Lubricants were evaluated on the basis of volatility and their ability to prevent fretting corrosion on tin-to-solder contacts. Limited tests were also done on their spreading characteristics, their thermal degradation properties, and their effect on contact resistance. The objective of the work was to develop guidelines in the selection of contact lubricants for field testing. The lubricants were ranked on the basis of weight loss from thin deposits of the samples on solder foil coupons at 65°C. Fretting experiments were done by forcibly moving a printed circuit card finger between a pair of spring contacts cut from actual cards and connectors. The time required for contact resistance to increase from a few milliohms to 2 \Omeg was determined as a function of the amount of lubricant present.

A Test of Noble Metal Slip-Ring Alloys for Use in Inertial Guidance Platforms

Lubricated slip-ring contact materials were life-tested in a nitrogen atmosphere and in a multichemical atmosphere that simulated the gases in an inertial guidance platform. The test mode was one that maximized the effects of debris accumulations and the generation of resistive films on infrequently wiped surfaces. The contacts that were lubricated with a four-ring polyphenyl ether had lower noise than ones lubricated with a blend of diester and chlorofiuorocarbon oils. The alloys grouped in decreasing order of performance as sliding contacts for inertial guidance platforms are as follows: Group I-ASTM B477; 4 Ni, Au; 1 Ni, Au electrodeposit; Group II-ASTM B541; 10 Cd, Au; Group III-54.5 Au, 37.5 Ag, 4 Cd, 4 In.

PETROLEUM AND ANTHROPOGENIC INFLUENCE ON THE COMPOSITION OF SEDIMENTS FROM THE SOUTHERN CALIFORNIA BIGHT1

ABSTRACT Low to high concentrations of petroleum hydrocarbons and industrial chemicals (polyphenyl ether, polychlorinated biphenyls, DDE; phthalates, adipates) have been detected in nearly all benthic and sandy intertidal sediment samples collected from the Southern California borderland. Low levels of petroleum contamination in combination with recent biogenic contributions were interpreted primarily on the basis of fully-saturated cycloalkanes in the absence of cyclic alkenes, the presence of a gas chromatographically-unresolved baseline envelope, and the presence of an homologous series of alkyl aromatic hydrocarbons. The inner basins of the Southern California Bight exhibit higher concentrations of weathered petroleum than either the farther offshore basins, or the sandy intertidal zone. Near Tanner-Cortez banks and in the San Nicolas Basin, sediments appear to contain unweathered petroleum and high levels of anthropogenic chemicals. The possible sources of hydrocarbons found in the Southern California borderland sediments, in addition to shipping losses and harbor traffic, include municipal and industrial waste waters, as well as previously-undetected submarine oil seeps, submarine chemical dumps, and geochemically-mature, organic-rich Tertiary shales.

Capillary gas chromatography of C6−C14 n-alkenes on polyphenyl ether and polyethylene glycol 4000

The retention indices (I) and their structural increments (σl/°C, H, Δl) of C6−C14 n-alkenes on polyphenyl ether (PFE) and C12−C14 n-alkenes on polyethylene glycol 4000 (PEG) at 20–160 °C have been determined and correlated with the molecular structure of the isomers. A number of common regularities in gas chromatographic behaviour on these liquid phases and squalane (SQ) [1–3] have been found. On PFE the elution order of isomeric n-alkenes is similar to that on SQ (except C8−C10 1-alkenes and cis-4-tetradecene), for pairs with cis- and trans-configuration it depends on the column temperature, position of double bond and the number of carbon atoms (n) in the molecule. On PEG the cis- are always retained longer than the corresponding trans-alkenes. The linear relationships between 1 and n on PFE and PEG are given in equation form.

Viscosity and Density Characteristics of Five Lubricant Base Stocks at Elevated Pressures and Temperatures

The absolute viscosities and densities of five lubricant base fluids (unformulated) were determined at pressures to 150,000 psig and temperatures to 300 F with a falling weight viscometer. The lubricants investigated were a sebacate ester, a TMP ester, SAE 20 mineral oil, a 5P4E polyphenyl ether, and a methyl chlorophenyl silicone. The falling weight viscometer and experimental procedures are discussed. Measured properties of the sebacate ester are in excellent agreement with the results of previous investigators. Computergraphics generated equations of viscosity, density, and pressure coefficient of viscosity vs pressure at each temperature are presented. Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Miami Beach, Florida, October 21–23, 1975

Capillary gas chromatography of n-alkyness : II. Variation of retention indices with temperature

The Kováts retention indices ( I of C 6C 14 n-alkynes on squalane (SQ), Apiezon L (ApL), polyphenyl ether (PFE) and polyethylene glycol 4000 (PEG) vary relatively slightly with temperature ( T) in the range 60–190°C. On SQ the I values of internal n-alkynes decrease and on PEG and PFE they increase with increase in T, while 1- and 3- n-alkynes have negative temperature increments on PEG. On SQ the 3-isomers show the greatest change of I with T, and on PEG (C 12C 14 n-alkynes) and PFE the smallest change. Equations for calculating I based on column temperature are given.

Determination of Hydrogen Sulfide in Heated Milks by Gas-Liquid Chromatographic Headspace Analysis

Abstract A rapid, accurate method for detecting and measuring hydrogen sulfide production during processing of milk products was developed. A gas-liquid chromatograph equipped with a flame photometric detector and a Teflon column containing 40/60 mesh Haloport-F treated with 12% polyphenyl ether and .5% orthophos-phoric acid was used for hydrogen sulfide analysis. Headspace sampling was accomplished by adding 10ml of water to the milk sample, forcing headspace vapors into a 6-port sampling valve attached to the chromatograph. A 1-ml vapor sample was flushed into the column for analysis. As little as 10 μ g of hydrogen sulfide/ml of milk were detected. Instrumental responses were compared to sensory evaluation of several heated milk samples. A correlation was established between hydrogen sulfide in milk headspace and the degree of cooked flavor determined organoleptically.

Capillary gas chromatography of n-alkynes : I. Retention indices

Retention indices ( I) of C 6C 14 n-alkynes have been determined on squalane, Apiezon L, polyphenyl ether and polyethylene glycol 4000 in the temperature range 60–190° and are correlated with the structure of the isomers. The effects on I of the position of the triple bond, of the chain-length and of the polarity of the liquid phase are discussed. Equations are presented which describe the linear dependences of I on the number of carbon atoms in the molecules, n. The best resolution of positional isomers has been obtained on squalane.

A Comparative Study of the Performance of Electrical Sliding Contact Lubricants in a Chemically Active Atmosphere

The performance of sliding contact lubricants including a diester-chlorofluorocarbon blend, a neopentylpolyolester-diester blend, a four ring polyphenyl ether, a perfluoroalkylPolyether, and a perfluorotributyl amine in an atmosphere composed of several chemical compounds has been determined. The chemical compounds were those that outgassed at 65°C from electro-mechanical assemblies normally used in guidance systems. A detailed gas chromatography/mass spectroscopy (GC/MS) analysis of this atmosphere and the compounds transferred to the lubricated sliding contact devices is presented. The performance of the lubricants was measured as a function of electrical noise and friction of the sliding contacts.

Polyphenyl ether, a liquid phase for the gas chromatographic—mass spectrometric analysis of monoterpene hydrocarbons

Polyphenyl ether, a liquid phase for the gas chromatographic—mass spectrometric analysis of monoterpene hydrocarbons

The elastohydrodynamic behaviour of polyphenyl ether

The paper describes measurements of the film thickness and traction given in elastohydrodynamic lubrication by polyphenyl ether. The film thickness is well below the theoretical value and very sensitive to temperature but its variation with load is of the theoretical magnitude. The tractional behaviour is more complex than that of mineral oils and this is thought to be due to the variation of the pressure distribution with speed and load. The results indicate that the fluid behaves elastically when the slip is small, even at the lowest load. Above a critical stress the relation between the shear stress and the rate of shear becomes non-linear. The non-Newtonian characteristics of this ’elastic’ fluid then become similar to those of a ‘viscous’ fluid.

Gas chromatographic mass spectrometric computer analysis of volatile components in blood plasma from hemodialysis patients

Low molecular weight volatile organics extracted from the plasma of patients before and after hemodialysis were analyzed by high resolution capillary gas chomatographic mass spectrometric computer methods. The volatile components were collected on a polyphenyl ether solid adsorbent prior to analysis. Identification of components was achieved by mass spectrometry. Quantitaive changes were observed in both the plasma and dialysate composition with time. The method described provides a new means whereby the 100 or so low molecular weight organic volatiles of plasma can be monitored during the dialysis procedure.

Investigation of the isomeric composition of polyphenyl ethers by high-temperature gas chromatography

Investigation of the isomeric composition of polyphenyl ethers by high-temperature gas chromatography

High-Temperature Stabilization of Polyphenyl Ethers by Soluble Metal-Organic Salts

A series of soluble metal phenoxides prepared from two phenols was investigated as high-temperature (to 371 C) anti-oxidants in polyphenyl ether (5P4E). Compounds from Group 1A (alkalis) and 2A (alkaline earths) were effective, but not in the same order as their inorganic oxide, hydroxide and carbonate counterparts studied earlier. High-temperature antioxidant activity of the phenoxides was not adversely affected by water-saturated air; the phenoxides were, however, subject to hydrolysis at 40 C by persistent exposure to liquid water. The phenoxides did not adversely affect the pyrolytic stability of the ether in the absence of air, although they were themselves slightly degraded. Presented at the 29th Annual Meeting in Cleveland, Ohio, April 28–May 2, 1974