Titanium glycolate

Soluble oil metal-working fluids, 1 22 Soluble oils, 15 240 Soluble silicates, 22 451-452 dissolution of, 22 455-456 history and applications of, 22 452 Soluble starch synthases, 12 492 Soluble titanium glycolate complexes, 25 87 Solute clearances... 

Fig. 14.49. Mechanism of the McMurry reaction. The heterocyclic monotitanium glycolates A and B or analogous dititanium glycolates decompose at higher temperatures via heterolytic cleavage of one of their C—O bonds and form the radical intermediate C. The alkene is formed by cleavage of the second C—O bond. This alkene is not obtained as a single stereoisomer because of the free rotation about the C—C(O) bond in the radical intermediate C. Note that the alkene is formed with a cis, fraraj-selectivity that is independent of the configuration of the titanium glycolate precursor(s).

A method for the mild catalysis for ester/transester reactions was developed by Siddiqui [2], using the polymeric titanium glycolate catalyst, (II). 

Samran, B., Aungkutranont, S., White, T., and Wongkasemjit, S. 2011. Room temperature synthesis of Ti-SBA-15 from silatrane and titanium-glycolate and its catalytic performance towards styrene epoxidation. J. Sol-Gel Sci. Technol. 57(2) 221-228. 

Thanabodeekij, N., Tanglumlert, W, Gulari, E., and Wongkasemjit, S. 2005. Synthesis of Ti-MCM-41 directly from silatrane and titanium glycolate and its catalytic activity. Appl. Organomet Ghem. 19(9) 1047-1054. 

Li CC, Li QH, Chen LB et al (2012) A facile titanium glycolate ptecursOT route to mesoporous Au/Li4Ti50j2 spheres for high-rate lithium-ion batteries. ACS Mater httrafaces 4 1233-1238... 

In this process, catalysts, such as boric acid, molybdenum oxide, zirconium, and titanium tetrachloride or ammonium molybdate, are used to accelerate the reaction. The synthesis is either carried out in a solvent (aUphatic hydrocarbon, trichlorobenzene, quinoline, pyridine, glycols, or alcohols) at approximately 200°C or without a solvent at 300°C (51,52). 

In the chemical industry, titanium is used in heat-exchanger tubing for salt production, in the production of ethylene glycol, ethylene oxide, propylene oxide, and terephthaHc acid, and in industrial wastewater treatment. Titanium is used in environments of aqueous chloride salts, eg, ZnCl2, NH4CI, CaCl2, and MgCl2 chlorine gas chlorinated hydrocarbons and nitric acid. 

Titanium tetraiodide can be prepared by direct combination of the elements at 150—200°C it can be made by reaction of gaseous hydrogen iodide with a solution of titanium tetrachloride in a suitable solvent and it can be purified by vacuum sublimation at 200°C. In the van Arkel method for the preparation of pure titanium metal, the sublimed tetraiodide is decomposed on a tungsten or titanium filament held at ca 1300°C (152). There are frequent hterature references to its use as a catalyst, eg, for the production of ethylene glycol from acetylene (153). 

Thionyl chloride Thiophosgene Titanium tetrachloride Trichloromethyl perchlorate Triformoxime trinitrate Trimethylacetyl chloride Trimethylene glycol diperchlorate Trimethylol nitromethane trinitrate... 

Using excess ethylene glycol is the usual practice because it drives the equilihrium to near completion and terminates the acid end groups. This results in a polymer with terminal -OH. When the free acid is used (esterification), the reaction is self catalyzed. However, an acid catalyst is used to compensate for the decrease in terephthalic acid as the esterification nears completion. In addition to the catalyst and terminator, other additives are used such as color improvers and dulling agents. For example, PET is delustred hy the addition of titanium dioxide. 

Titanium dioxide Sodium starch glycolate Talc... 

All commercial materials are based on calcium hydroxide and liquid alkyl salicylates (Prosser, Grolfman Wilson, 1982) and are supplied as a two-paste pack. Zinc oxide is sometimes added to the calcium hydroxide, as are neutral fillers. A paste is formed from this powder by the addition of a plasticizer examples include A-ethyl toluenesulphonamide (o- orp-) and paraffin oil, with sometimes minor additions of polypropylene glycol. The other paste is based on an alkyl salicylate as the active constituent containing an inorganic filler such as titanium dioxide, calcium sulphate, calcium tungstate or barium sulphate. Alkyl salicylates used include methyl salicylate, isobutyl salicylate, and 1-methyl trimethylene disalicylate. An example of one commercial material, Dycal, is given in Table 9.7, but its composition has been subjected to change over the years. 

Dimethyl terephthalate, Titanium butoxide See Dimethyl terephthalate Ethylene glycol, Titanium butoxide... 

SOLINOX SO,. Linde NO,] A process for removing both NOx and SOx from fluegases. The SOx is removed by scrubbing with tetra-ethylene glycol dimethyl ether, circulated in a packed tower (the Selexol process). The NOx is destroyed by Selective Catalytic Reduction ( SCR). The sorbent is regenerated with steam the SOx is recovered for conversion to sulfuric acid. Developed by Linde in 1985 and used in a lead smelter in Austria and several power stations in Germany. In 1990 it was announced that it would be used at the titanium pigment plant in The Netherlands operated by Sachtleben. 

Furthermore, the environmental impact of PET production should be reduced by substituting the commonly used antimony-based catalyst for an antimony-free catalyst leg, for a titanium-based catalyst. The pollution by liquid effluents could be reduced by installing a reverse-osmosis unit on top of the glycol distillation unit for the purification of water from the esterification process. 

Yamada, T., Effect of titanium dioxide on direct esterification between terephthalic acid and ethylene glycol,. /. Appl. Polym. Sci., 45, 765-781 (1992). 

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