Dispersant with zinc

Tube side Cooling water, 60-80°F (16-27°C), high hardness and silica, treated with a dispersant and zinc... 

The most common use of curing agents is with carboxylic latices. Isocyanates and melamines can be used but zinc oxide is the most common curing agent. Zinc oxide cross-links carboxylated latices and improves bond strength by ionomer formation [78]. Carboxylated polychloroprene reacts slowly with zinc oxide in dispersed form, causing a gradual increase in adhesive gel content. This can lead to restricted adhesive shelf life. Resin acid sites compete with the polymer acid sites for Zn(II). The more resin acid sites, the more stable the adhesive. 

The researches of ZnCFO compatibility with the matrix of isoprene rubber in plasticorder "Brabender" PLE 6511 have shown, that the disperse process of composite is accompanied by lower power consumption and its best compatibility in comparison with zinc oxide (fig. 4). The absence of ZnCFO particles as extraneous impurities in rubber mix also was visually observed, while the zinc oxide particles were well appreciable [7],... 

The question immediately raised is would this technique portray an opposite or negative adhesion response if applied to a polymer blended system where no interfacial bonding could be present Such a system would be cis-polybutadiene and high molecular weight polyisobutylene restricted to that portion of the blend system where polyisobutylene is the minor dispersed phase in cis-polybutadiene. A high molecular weight polyisobutylene [L-300 Vistanex (Enjay Chemical Co.)] was compounded with zinc oxide, sulfur, and TMTDS and then dissolved in hexane. cis-Polybutadiene (Phillips Chemical Co.) was also mixed with... 

In low pH cooling waters (pH 6.0 to 7.4), when treating with zinc programs, levels of 3 to 5 ppm of soluble zinc can often be obtained, which tends to provide good corrosion protection to carbon steel. Its solubility rapidly decreases as the pH rises it may only be 0.2 to 0.3 ppm or less in high pH cooling water (say pH 8.3 and above), giving rise to the risk of zinc precipitation in the bulk water. This is partly overcome by the incorporation of zinc stabilizers ( zinc dispersants or zinc enhancers ) in the formulation. 

Mixtures of metallic detergents, such as phenates, sulfonates, phosphonates, and salicylates with ashless dispersants such as succinimides and benzylamine, together with zinc dialkyldithiophosphate (ZDDP), can lead to new effects. The possible interactions between these main additives used in lubricating formulations when dissolved/dispersed in hydrocarbon media are shown in Fig. 2.8 together with an indication of the intensity of those respective interactions. 

The tribofilms formed from a ZDDP were composed of long chain phosphates with zinc as a cation but with a mixture of a ZDDP + detergent and ZDDP + dispersant, only short-chain phosphates with zinc and calcium as cations are formed in the presence of a sulfide (Barcroft and Park, 1986 Willermet et al., 1995a). 

In 1973, the direct potassium metal reduction of zinc salts was reported.3 This active zinc powder reacted with alkyl and aryl bromides to form the alkyl- and arylzinc bromides under mild conditions.4 The reduction of anhydrous zinc salts by alkali metals can be facilitated through the use of electron carriers. Lithium and sodium naphthalenide reduce zinc salts to give highly reactive metal powders under milder and safer conditions. Graphite5 and liquid ammonia6 have also been employed as electron carriers in producing zinc powders. A highly dispersed reactive zinc powder was formed from the sodium metal reduction of zinc salts on titanium dioxide.7... 

Several catalysts were prepared from chemicals of highest available grade. Mechanistic studies were performed using colloidal dispersions of zinc oxide, ZnO, which contained particles with a mean diameter of 5 nm (Bahnemann, D. W. Kormann,... 

Reduction of a,a -dibromo ketones. Reduction of 2,4-dibromo-2,4-dimethyl-pentane-3-one (1) with ultrasonically dispersed mercury in the presence of a ketone such as acetone leads to a 4-methylene-l,3-dioxolane (2) in about 50% yield. A similar reaction has been observed in the reduction of dibromo ketones with zinc in dimethylformamide (5, 221). 2-Oxyallyl cations such as a have been invoked as intermediates in reductions of dihalo ketones with various metals. 

Thus any advantage of molybdenum disulphide in an oil in reducing friction will be limited to the boundary and mixed lubrication regions, where the reduction in friction may be considerable. One theoretical analysis suggested that the influence of the dispersed powder depends only on particle shape, size and concentration , or in other words that the dispersed powder is simply forming a physical barrier between the interacting surfaces. It would follow that the same effect could be produced by other dispersed solids, and this was confirmed by studies with zinc sulphide, zinc pyrophosphate and calcium hydroxide. 

The molecular refraction and dispersion of zinc diethyl compared with tin tetraethyl is as follows — ... 

Very few CPs are produced in bulk quantities. Polyphenylene sulfide, a member of the third generation of polymers, was produced in bulk quantities many years before CPs were established and its dopability was elucidated. Polyethylenedioxythiophene is commercially available as a water-based colloidal dispersion (Baytron P water dispersion), and presumably as dispersible powders. The powders with a conductivity of 5-10 S/cm can be dispersed in thermoplastic polymers and in organic solvents such as xylene. Polyaniline doped with dodecylbenzene sulfonic acid and complexed with zinc dodecylbenzene sulfonate is commercially available as a powder, which can be dispersed in polyolefins. The same polymer doped with p-toluenesulfonic acid is also available as a dispersible powder, Ormecon, and in a predispersed form for solution processing in polar and nonpolar media. Based on Ormecon PANi, there are many commercial products marketed for many different applications. 

Sodium has been dispersed on the surface of alumina, sodium chloride, or titanium dioxide by stirring with excess support at 180-190°C under argon. The first was the most effective for reducing titanium(III) chloride for the McMurray reaction 5.1, being better than the commonly used reduction with zinc.17... 

One of the ways of improving wear resistance and reliability of sealing elements is filling of porous semis by components able to form a secondary porous system [146]. For example, a blank of a polyurethane foam is impregnated with a mixture of dispersed PE with an inhibited lubricant. The formation of a gel under certain temperature regimes is accompanied by phase distribution within the material. The contact surface of the blank is cleaned by acetone to remove the lubricant. As the acetone evaporates, the prepared zones are zinc-plated and pores freed from the lubricant become filled with zinc. This makes the coating adhere strongly to the surface and allows zinc to penetrate to a depth acceptable for wear limits. 

Uses Pigment for interior/exterior paints, printing inks, rigid/flexible PVC Features Exc. durability due to its crystal stabilization with zinc easy to disperse... 

It is known that zinc cations of the ZnO and/or zinc compounds react with the organic accelerators thus giving zinc complexes accelerators. This is one of the most important stages of the vulcanization scheme [50, 51]. It has been suggested that the better zine dispersing in the system ends with zinc complex generating and the zine ions are free to form active accelerator complexes. By reason of that, zine ion is supposed to be the central atom in the accelerated sulfur vulcanization [46]. This idea has remained indivertible for the last 25 years. 

---