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Corrosion inhibitors thermal stability

The PCAs tend to exhibit good performance as iron dispersants, phosphate stabilizers, and corrosion inhibitors, with additional good thermal and hydrolytic stability. [Pg.451]

In the 1960s organic phosphates (phosphonates) were introduced, such as ATMP and HEDP, which proved to be superior to phosphates in many ways, including their thermal stability and sequestering power. Although the corrosion inhibition of carbon steel, derived solely from phosphonates, remains a weak feature, this can be enhanced by syneigizing with other inhibitors, such as zinc. Like the polyacrylates, phosphonate chemistry has endured and remains a second basic DCA constituent of almost all modern formulations. [Pg.147]

The 1980s produced a wide range of new copolymers, often using chemistry based on acrylic acid with sulfonic acid, sulfonated styrene, or sulfonated acrylamide. Also, new products were introduced based on phosphinocarboxylic acids. All these modern organic polymers found immediate favor as improved iron dispersants, phosphate stabilizers, or corrosion inhibitors, with good thermal and hydrolytic stability. [Pg.153]

Soybean fatty acids are conjugated thermally or catalytically to yield dimer and tri-mer polybasic acids (Erhan et al., 2005). Hydrolyzed dimer acids improve color and oxidative stability. These are used in polyamide resins, paints, plastics, and coatings, bodying/curing/flexibilizing agents, corrosion inhibitors, antiwear agents, lubricants, fuel, and lubricant additives (Antonucci et al., 1984 Bhowmick Basu, 1988 Kale et al., 1991 Savastano, 2001 Watanabe et al., 1996). The annual dimer acid production is about 18,000 MT (20,000 t). [Pg.592]

Derivatives of cyclic phosphazenes have further been used as thermal stabilizers of various materials, as corrosion inhibitors, antifriction agents,... [Pg.273]

All cases of accidental chromate poisoning in cattle have resulted from the exposure of animals to chromate compounds associated with oil-field activities. Chromates are used as a corrosion inhibitor between the pipe and casing and are often added to drilling fluids (in the form of chromeUgnosulfQnate) to improve thermal stability. One recorded case involved 20 mature cows and their 8-month-old calves. [Pg.154]

Most effects of elevated temperatures are adverse to corrosion inhibition. High temperatures increase corrosion rates (about double for a 15°C rise at room temperature), and they decrease the tendency of inhibitors to adsorb on metal surfaces. Precipitate-forming inhibitors are less effective at elevated temperatures because of the greater solubility of the protective deposit. Thermal stability of corrosion inhibitors is an important consideration at high temperatures. Polyphosphates, for example, are hydrolyzed by hot water to form orthophosphates that have little inhibitive value. Most organic compounds are unstable above about 200°C (see Table 17.1) hence, they may provide only temporary inhibition at best. [Pg.446]

As outlined above, surfactants are added to acids to perform one or more of several needed functions. However, other chemicals are also added to the acid. These additives inclnde corrosion inhibitors [IS], iron control agents [J9, 20], hydrogen sulfide scavengers [21], scale inhibitor [22] and clay stabilizers [23], It is very important to perform compatibility tests of the selected surfactant with the acid formnla, especially in this complex environment. Also, some of the snrfactants are nsed in high temperature and high salinity applications. Therefore, it is necessary to ensure thermal stability of these surfactants nnder these harsh conditions. [Pg.331]

The evaluation of corrosion inhibitor effectiveness is significantly different in many respects from corrosion testing for the purpose of evaluating material performance. The addition of a chemical to a corroding system requires compatibility, chemical and thermal stability, and in some cases physical stability as well. Transport properties become important where localized or gasphase corrosion (dew point) are an issue. Finally, no corrosion inhibitor, no matter how effective in preventing corrosion, can be considered successful if it causes process upsets. This latter aspect is usually summarized under secondary properties testing [7] (cf. also Chapter 1 in this book). [Pg.481]

Thermal Stability It is known that corrosion inhibitor effectiveness varies with temperature. This can be due to chemical degradation, decreased adsorption at higher temperature, or changes in surface properties (e.g., iron carbonate converts to magnetite at higher temperature). [Pg.481]

Uses Surfactant intermediate, engine oil lubricant additive, viscosity and pour-point improver, plasticizer, epoxy, antifreeze lubricant, control for leather goods and corrosion inhibitor sizing agent in the alkaline production of paper Features Good thermal stability melt processable cost effective Properties Cl, amber liq, sp, gr, 0,955 vise, 250 cs b.p. 235 5 mm Hg flash pt. (PM-CC)195C... [Pg.136]

Uses Antiwear additive, EP agent, antioxidant, stabiiizer, anlifoam and demulsifier for hydraulic fluids corrosion inhibitor for steel and yellow metal Features Imparts extended oil life and pump durability exc. thermal/oxidation stability... [Pg.393]

Uses Corrosion inhibitor, emulsifier for syn. and semisyn. aq. cutting fluids, conventional cutting fluids, aq. hydraulic fluids, aq. offshore fluids Features Improved lubricity, emulsion stability good thermal stability low foaming ... [Pg.866]

Uses Surface active antistat for syn. fibers, caqpets high thermal stability built-in corrosion inhibitor Properties Liq. 45% act. [Pg.1618]

For adequate corrosion protection of a metal in an aggressive environment, it is important to select materials and techniques that are compatible. For example, addition of an organic inhibitor (e.g. pyridines, pyrimidines, quinolines) is sufficient to mitigate corrosion of metals in many corrosive media. However, these inhibitors have shown only limited success due to solubility and/or thermal stability problems in high-temperature, concentrated salt solutions such as in chemical heat pumps (Priyantha et al., 2003). [Pg.181]

The above discussed results elucidate the mechanism of action of cerium oxide coatings as effective cathodes and of cerium ions (when they are present as a component of the corrosion medium) - as inhibitor having oxidative action, leading to improvement of the corrosion stability of stainless steels. They explain the improved ability of the steel to undergo passivation, respectively to recover its passive state in cases of disruption of its surface passive film - especially in this specific case, studied by us, i.e. disruption as a result of thermal treatment. [Pg.264]


See other pages where Corrosion inhibitors thermal stability is mentioned: [Pg.110]    [Pg.133]    [Pg.110]    [Pg.133]    [Pg.400]    [Pg.111]    [Pg.226]    [Pg.111]    [Pg.38]    [Pg.573]    [Pg.6]    [Pg.128]    [Pg.1105]    [Pg.148]    [Pg.32]    [Pg.440]    [Pg.144]    [Pg.470]    [Pg.676]   
See also in sourсe #XX -- [ Pg.481 ]




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