Thixotropic reactions

Alkanolamine Chelates. Alkanolamine chelates, which are prepared by reaction of tetraalkyl titanates with one or more alkanolamines, are used primarily in cross-linking water-soluble polymers (qv) (see Alkanolamines) (104). The products are used in thixotropic paint emulsion paints, in hydrauhc fracturing and drilling of oil and gas wells, and in many other fields. The stmcture of... 

The alkoxy titanate compounds formed by reaction of one mole of tetraalkyl titanate with one mole of a dialkanolamine are excellent esterification catalysts for the manufacture of phthalate-based plasticizers (112). If a 1 1 molar mixture of alkanolamine and water is used ia place of the alkanolamine, oligomeric titanate complexes are formed, which have high catalyst activity and can be used as thixotropic additives to paints and other aqueous coating formulations (113). 

As substituent uniformity is increased, either by choosing appropriate reaction conditions or by reaction to high degrees of substitution, thixotropic behavior decreases. CMCs of DS >1.0 generally exhibit pseudoplastic rather than thixotropic rheology. Pseudoplastic solutions also decrease in viscosity under shear but recover instantaneously after the shear stress is removed. A plot of shear rate versus shear stress does not show a hysteresis loop. 

Mixtures of the monotriethanolamine titanate and polyols, such as fructose and sorbitol, imparted thixotropic properties to polymer-containing cement (107). A similar reaction of triethanolamine and tetraalkyl titanates previously treated with stearic acid gives the corresponding 1-acyloxytitatranes (108). Aqueous dispersions of these materials can be used to treat fabrics to impart a high degree of water repellency. 

Thixotropic agent Undergo reversible crosslinking reactions via hydrogen bridge bonds, forming a gel structure Added as the last ingredient in the formulation. Mainly used for water-based acrylics... 

Naphthali-Sandholm method, 404 dgorithm flowsketch, 411 Nitric acid reactor, 576 Nitrogen fixation, 574,578,588 Nitrotoluene isomers separation, 544 Noncatalytic reactions with solids, 595 Non-Newtonian liquids, 100, 103-109 Bineham. 104.105.107-109 dilatant, 103, 104 laminar flow, 108,109 pressure drop in lines, 106, 109 pseudoplaslic, 103, 104 rheopectic, 104,105 slurries, 71 thixotropic, 104-106 viscoelastic, 105, 106 Notation, 672 NPSH, pumps, 133,146 centrifugal pumps, 146 positive displacement pumps, 134, 135 various pumps, 144 NRTL equation, 475... 

The silanol groups on the polymer particle surface play a very important role upon the particle aggregation such as the interparticle hydrogenbonding and the hydrothermal reaction thereafter. The hydrogen bond between these particles is about 5 times stronger than that of electrostatic and van der Waals forces, but weak enough to be broken by a mechanical force in such cases as the thixotropic behaviour of aerosil powder mixed in... 

A thixotropic starch was produced in reactions of POCl3-crosslinked starch with unsaturated aliphatic aldehydes.1361 Starch phosphates have been crosslinked by various aliphatic and aromatic aldehydes in the presence of urea, melamine, and similar compounds. Among several aldehydes tested[formaldehyde, propanal (propionaldehyde), glyoxal, glutaraldehyde, 2-hydroxyadipaldehyde (2-hydroxy -1,6-hexanedial), and some aromatic aldehydes], only those products that had reacted with glyoxal were insoluble in water.1322 Significant increases in viscosity occurred after starch phosphates having a low DS were treated with urea.1590... 

The rates of absorption of sulfur oxides in milk of lime and of solution of the slaked lime are considerably faster than the analogous reactions with limestone. For a given removal efficiency, therefore, the absorber is considerably smaller than that for limestone. This helps to reduce capital costs and the power consumed in recirculating the slurry. However, because of the rapid precipitation of calcium sulfite hemi-hydrate with some gypsum, the particles tend to be finely divided and form a thixotropic sludge which is difficult to de-water for disposal [12.1]. 

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