Modifications acid control

The synthesis of the crystal modification is controlled primarily by the finishing technique of the crude pigment. There are basically two different methods to produce a finely dispersed pigment treatment with acid to form copper phthalocyanine salts, followed by precipitation in water on the one hand, and mechanical treatment (milling, kneading) on the other hand. The following methods are used ... 

In another approach, the SAN backbone of ABS was modified through copolymerization with maleic anhydride. This modification introduced controlled amounts of an anhydride functionality on ABS, which upon subsequent melt blending with a PA reacts to form a graft copolymer of SAN and PA which effectively compatibilizes the blend. Commercial blends of ABS with PA-6 and PA-66, introduced by Monsanto under the trade name of Triax 1000, utilize this reactive compatibilization technology [Lavengood et al, 1987]. In another technique of reactive compatibilization, commercial grades of ABS were directly modified by reactive extrusion with maleic anhydride or fumaric acid and then melt blended with PA-6 and optionally adding small amounts of functionalized EP mbber [Akkapeddi et al, 1990]. 

Modification of redox and catalytic properties of Keggin-type, Sb-doped P/Mo polyoxometalates in the selective oxidation of isobutane to methacrylic acid control of preparation conditions... 

Selection of pollution control methods is generally based on the need to control ambient air quaUty in order to achieve compliance with standards for critetia pollutants, or, in the case of nonregulated contaminants, to protect human health and vegetation. There are three elements to a pollution problem a source, a receptor affected by the pollutants, and the transport of pollutants from source to receptor. Modification or elimination of any one of these elements can change the nature of a pollution problem. For instance, tall stacks which disperse effluent modify the transport of pollutants and can thus reduce nearby SO2 deposition from sulfur-containing fossil fuel combustion. Although better dispersion aloft can solve a local problem, if done from numerous sources it can unfortunately cause a regional one, such as the acid rain now evident in the northeastern United States and Canada (see Atmospheric models). References 3—15 discuss atmospheric dilution as a control measure. The better approach, however, is to control emissions at the source. 

Additives. Because of their versatility, imparted via chemical modification, the appHcations of ethyleneimine encompass the entire additive sector. The addition of PEI to PVC plastisols increases the adhesion of the coatings by selective adsorption at the substrate surface (410). PEI derivatives are also used as adhesion promoters in paper coating (411). The adducts formed from fatty alcohol epoxides and PEI are used as dispersants and emulsifiers (412). They are able to control the viscosity of dispersions, and thus faciHtate transport in pipe systems (413). Eatty acid derivatives of PEI are even able to control the viscosity of pigment dispersions (414). The high nitrogen content of PEIs has a flame-retardant effect. This property is used, in combination with phosphoms compounds, for providing wood panels (415), ceUulose (416), or polymer blends (417,418) with a flame-retardant finish. 

Com symps used in ice cream and fro2en desserts are generally 36- or 42-DE acid-converted symps. The symp serves primarily to provide maximum flexibiUty in adjusting flavor, texture, body, and smoothness. It also aids in grain control and in the modification of meltdown and shrinkage characteristics of the fro2en product. 

Hydrochloric acid/stannous chloride. Modifications of the standard HC1 cleaning program to aid control corrosion of exposed steel include the addition of HF, as discussed earlier, but also stannous chloride. Where the cleaning program is likely to remove considerable volumes of rust and magnetite, even in the presence of a nitrogen- and sulfur-based proprietary corrosion inhibitor, rapid corrosion of exposed steel may develop. This is because the ferric ions (Fe3+) released from ferric oxide act to reduce the exposed steel to ferrous ions (Fe2+). 

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