Iron dispersant polymers

However, it cannot be denied that water treatment chemistry researchers have made significant progress in recent years. And some of the newer chemicals have most definitely added value to customers processes by enabling cooling systems to be operated under levels of stress and with extreme waterside conditions considered impossible to treat only a dozen years ago (the phosphate stabilizers and iron dispersant polymers are good examples of such useful developments). 

A chelant—polymer combination is an effective approach to controlling iron oxide. Adequate chelant is fed to complex hardness and soluble iron, with a slight excess to solubilize iron contamination. Polymers are then added to condition and disperse any remaining iron oxide contamination. 

Problem-specific polymers include terpolymers, used for iron dispersion, iron transport, and silica control. 

Dispersants are often also specified, depending on the level of iron and BW sludge present. Iron transport polymers such as acrylic acid/sodium 3-allyloxy-2-hydropropane (AA/COPS) and phos-phinocarboxylic acid (PCA) usually are the most suitable. 

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. 

Basic solvents and high temperatures favor the binding of metal carbonyls to polymers. Stable colloidal dispersions are formed on fire tiiermolysis of carbonyls in dilute polymeric solutions. For example, iron dispersion containing 5-10-mn particles have been produced. Nanoparticles of this type are very reactive. Particles smaller than 10 nm are superparamagnetic, while the magnetic hysteresis is observed for particle sizes between 10 and 20 run. 

The thermal reaction of cis or trans 1,4-poly(butadiene) with iron carbonyls results in geometrical isomerization of the alkenyl moieties and formation of polymers containing conjugated diene) iron tricarbonyl units. In the course of our continuing studies of the formation of stable colloidal iron dispersions by thermal decomposition of metal carbonyls in the presence of functional polymers, some aspects of this work have been repeated. Our objective was to isolate the soluble organometallic polymer which was intermediate to particle nucleation and independently examine the intramolecular condensation of metal atoms to yield metal clusters and metal particles. In this paper, the structure of the intermediate obtained on thermolysis of an excess of FeCCO) in a dilute xylene solution of c/5-poly(butadiene) has been described. 

If deposits are minimized, the areas where caustic can be concentrated is reduced. To minimize the iron deposition in 6.895-12.07 x 10 Pa boilers, specific polymers have been designed to disperse the iron and keep it in the bulk water. As with phosphate precipitation and chelant control programs, the use of these polymers with coordinated phosphate—pH treatment improves deposit control. 

Polymer/phosphate/chelant formulation. General purpose application, but good iron and phosphate dispersion. 

Low iron levels in the feed are essential to avoid damage to the electrode from iron deposition. This is achieved only by correct condensate line corrosion treatment. Polymer dispersants should be fed direct to the feed line and boiler to ensure particulate iron is effectively removed with the BD. 

NOTE This formula is designed for removing calcium and iron foulants. Use at 300 ppm in the boiler. This produces 37 ppm of active polymer for dispersancy and 18 ppm active phosphonate for threshold stabilization. 

There is considerable interest in developing new types of magnetic materials, with a particular hope that ferroelectric solids and polymers can be constructed— materials having spontaneous electric polarization that can be reversed by an electric field. Such materials could lead to new low-cost memory devices for computers. The fine control of dispersed magnetic nanostructures will take the storage and tunability of magnetic media to new levels, and novel tunneling microscopy approaches allow measurement of microscopic hysteresis effects in iron nanowires. 

Manson (72,) expanded the concept to the solid state by observing that the strength of composite materials also depended upon the acid-base interaction between continuous and dispersed phases. More directly, Vanderhoff et al. (21) addressed the issue of adhesion of polymeric materials to corroded steel. They synthesized eight corrosion products of iron, and used the interaction scheme developed by Fowkes and Manson first to characterize the iron corrosion products as Lewis acids or bases and then to select polymer vehicles for practical coating systems. Such results were employed to enhance the adhesion of epoxy systems to substrates which were predominantly iron oxide in nature. A good overview of these Issues was presented by Fowkes in 1983 (74). ... 

Evaluation of the Copolymers The polymer solutions were evaluated for their deposit control and dispersant activities. The tests included calcium phosphate inhibition, calcium carbonate inhibition, iron oxide dispersion, and clay dispersion. The procedures for these tests have been previously reported (12). A commercially available polyacrylic acid was also tested for comparison. The results are shown in Tables II to V. 

As shown In Tables IV and V, copolymers were quite effective in dispersing iron oxide and clay as compared to polyacrylic acid. Among the polymers tested, acrylic acid/N-(2-hydroxyethyl)acrylamide seemed to be the most effective. 

Transition metal compounds, such as organic macrocycles, are known to be good electrocatalysts for oxygen reduction. Furthermore, they are inactive for alcohol oxidation. Different phthalocyanines and porphyrins of iron and cobalt were thus dispersed in an electron-conducting polymer (polyaniline, polypyrrole) acting as a conducting matrix, either in the form of a tetrasulfonated counter anion or linked to... 

MA/EA/VA) (polymer is approx. 80% hydrolyzed maleic anhydride, 10% ethyl acrylate, 10% vinyl acrylate) has been available for many years and exhibits properties similar to those of PMA. It cannot operate at the same extremes of service, but is of lower cost and competes well with other technologies. It has better general dispersion properties than many polyacrylates and is less sensitive to soluble iron. It can often replace polyacrylates as a phosphonate activity enhancer. 

Cumbal and Sengupta (2005) produced an effective arsenic removal system by dispersing high-surface area iron (oxy)(hydr)oxide nanoparticles within a base (anion exchange) polymer for permeable matrix support (Table 7.1). The polymer consisted of a quaternary ammonium functional group within a styrene-divinylbenzene matrix. The addition of the nanoparticles improved arsenic removal when compared with the polymer alone. 

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