Oxidation stability composition

Lube oil extraction plants often use phenol as solvent. Phenol is used because of its solvent power with a wide range of feed stocks and its ease of recovery. Phenol preferentially dissolves aromatic-type hydrocarbons from the feed stock and improves its oxidation stability and to some extent its color. Phenol extraction can be used over the entire viscosity range of lube distillates and deasphalted oils. The phenol solvent extraction separation is primarily by molecular type or composition. In order to accomplish a separation by solvent extraction, it is necessary that two liquid phases be present. In phenol solvent extraction of lubricating oils these two phases are an oil-rich phase and a phenol-rich phase. Tne oil-rich phase or raffinate solution consists of the "treated" oil from which undesirable naphthenic and aromatic components have been removed plus some dissolved phenol. The phenol-rich phase or extract solution consists mainly of the bulk of the phenol plus the undesirable components removed from the oil feed. The oil materials remaining... 

Aqueous polynitrile oxide curing compositions, with good storage stability, have been patented (525). The compositions comprise aqueous dispersions containing nitrile oxides and are useful for coating systems that are cured at room temperature without the release of byproducts. Latexes are cured by mixing a polymer latex with a stable polynitrile oxide, for example, 2,4,6-triethylbenzene -1,3-dicarbonitrile oxide, and removing water from the mixture. 

This research was an attempt to develop new polymers with the mechanical properties of polyarylene ethers and the dielectric properties of fluoropolymers. After initially testing the viability of the [2n+ 2n] cyclodimerization reaction for preparing high-molecular-weight polymers and testing the dielectric properties of these polymers, two polymers (one thermoplastic and one thermoset) were prepared in larger quantities to evaluate the thermal and mechanical performance of these novel compositions. The high Te thermoset was also quantitatively tested for thermal/oxidative stability. 

The production of endohedral fullerene complexes in visible amounts was first accomplished by a pulsed laser vaporization of a lanthanum oxide-graphite composite rod in a flow of argon gas at 1200 °C [66]. In this procedure, the newly formed endohedrals, together with empty fullerenes, sublime readily and are carried away in the flowing gas, depositing on the cool surfaces of the apparatus. This sublimate contains the complexes La CgQ, La C74 and La Cg2 (Figure 1.9). Among these, the endohedral molecule La Cg2 exhibits an extra stability. It can... 

As mentioned earlier PMR polyimide thermosts are used as matrix resins for glass- and carbon fiber composites, mainly in aeroengine applications. At this point it has to be mentioned that the thermal oxidative stability of a PMR composite is dependent on the type of fiber used (113) and the cure conditions (time/temperature/atmosphere) employed for molding. Very interesting is the observed higher thermal oxidative stability of PMR-II composites when cured/-... 

C capability. A resin coded AFR 700, based on a NE/HFDE/PPDA backbone with a stoichiometry imbalance, providing a prepolymer with a mixture of NE and amine/or anhydride endcaps, as is shown idealistically in Fig. 39. The thermal oxidative stability improvements vis a vis PMR-15 are presumably achieved because of a reduced aliphatic (NE) endgroup concentration. Unfortunately, no publication has appeared in the open literature on the mechanical performance of AFR-700 composition. 

The major concern was the thermal oxidative stability performance of the new resin. Weight loss measurements at 250,285 and 300 °C provided comparable low values at 250 and 285 °C. However, at 300 °C, the B1 composite exhibited a marketly lower weight loss than PMR-15. The temperature capability of B1 composite is obvious from Fig. 41, where the flexural properties of resins are plotted as a function of the ageing time at 285 °C. PMR-15 seems to be a superior resin in this test. 

Throughout this chapter the chemical concepts employed to synthesize and cure addition poly(imides) have been discussed and their use as matrix resins for fiber composites has frequently been mentioned. The most important property of the imide backbone structure is the inherent thermal stability. The target of achieving the temperature performance of linear poly(imide) has not been reached, because of the aliphatic nature of the reactive endgroups, and because of the low molecular weight of the imide backbone required for processing. Future developments of addition polyimides will, as in the past, focus on the requirement of high thermal and thermal oxidative stability of the crosslinked... 

Poly[2,2 -(m-phenylene-5,5 -benzimidazole)] (PBI) is a very high glass transition temperature (Tg 430°C), commercially available material. It possesses excellent mechanical properties, but is difficult to process into large parts and has high moisture regain and poor thermo-oxidative stability at temperatures above approximately 260 °C. Polyimides, especially the thermoplastic polyimides, offer attractive thermo-oxidative stability and processibility, but often lack the thermal and mechanical characteristics necessary to perform in applications such as the matrix for high use-temperature (over 300 °C) structural composites (for example, carbon fiber reinforced) for aerospace use. The attempt to mitigate... 

Relatively few processible polyimides, particularly at a reasonable cost and in reliable supply, are available commercially. Users of polyimides may have to produce intractable polyimides by themselves in situ according to methods discussed earlier, or synthesize polyimides of unique compositions in order to meet property requirements such as thermal and therm oxidative stabilities, mechanical and electrical properties, physical properties such as glass-transition temperature, crystalline melting temperature, density, solubility, optical properties, etc. It is, therefore, essential to thoroughly understand the structure—property relationships of polyimide systems, and excellent review articles are available (1—5,92). 

Although these composite fibers were developed lor reverse osmosis lltcir acceptance in the desalinatiun industry has been limited due to insufficient selectivity and oxidative stability. The concept, however, is extremely viable composite membrane fiat films made from interfacial polymerization have gained wide industry approval. Hollow libers using Ibis technique to give equivalent properties and life, yet lo be developed, should be market tested during the 1990s. 

Lipids. See also Lipid composition Lipid oxidation/stability characteristics of, 425, 432 crystal characterization, 575-579 extraction of... 

The oxidative stability of an oil depends on the fatty acid (FA) composition and triacyl-glycerol (TAG) structure, as well as on non-TAG components, such as tocopherols, carotenoids, ascorbic acid, citric acid, free fatty acids, and sterols, which may either prevent or promote oxidation. Several investigations have reported correlations of FA composition, TAG structure, and oxidative stability (135-140). For example, the oxidative stability of purified TAG from soybean oil (SBO) in air in the dark at 60°C is correlated positively with a greater concentration of oleic acid (O) and lower concentrations of linoleic (L) and linolenic (Ln) acids of SBO TAG. 

Thorsteinson et al.21 found a material consisting of mixed oxides of composition Mo0.6i V0.3iNb0.o8 to have optimum properties for the oxy-dehydrogenation of ethane. The better catalysts are characterized by a broad X-ray diffraction band near 4.0 A which may point to the presence of the compound VMo3Oii+x described by Andrushkevich.132 The presence of Nb stabilizes the catalyst against oxidation and reduction. 

Fantoni, C.M., Cuccio, A.P. and Barrera-Arellano, D. (1996) Brazilian encapsulated fish oils Oxidative stability and fatty acid composition. J. Am. Oil Chem. Soc., 73, 251-253. 

Charmley, E., Nicholson, J.W.G. 1995. Influence of dietary fat source on oxidative stability and fatty acid composition of milk from cows receiving a low or high level of dietary vitamin E. Can. J. Anim. Sci. 74, 657-664. 

Goering, H.K., Gordon, C.H., Wrenn, T.R., Bitman, J, King, R.L., Douglas, F.W.. 1976. Effect of feeding protected safflower oil on yield, composition, flavor and oxidative stability of milk. J. Dairy Sci. 59, 416-425. 

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