Titanate dispersion

Various investigations have considered the effects of titanate treatments on melt rheology of filled thermoplastics [17,41]. Figure 10, for example, shows that with polypropylene filled with 50% by weight of calcium carbonate, the inclusion of isopropyl triisostearoyl titanate dispersion aid decreases melt viscosity but increases first normal stress difference. This suggests that the shear flow of the polymer is promoted by the presence of titanate treatment, and is consistent with the view that these additives provide ineffective coupling between filler particles and polymer matrix [42]. 

Chemical Grafting. Polymer chains which are soluble in the suspending Hquid may be grafted to the particle surface to provide steric stabilization. The most common technique is the reaction of an organic silyl chloride or an organic titanate with surface hydroxyl groups in a nonaqueous solvent. For typical interparticle potentials and a particle diameter of 10 p.m, steric stabilization can be provided by a soluble polymer layer having a thickness of - 10 nm. This can be provided by a polymer tail with a molar mass of 10 kg/mol (25) (see Dispersants). 

Organic titanates perform three important functions for a variety of iadustrial appHcations. These are (/) catalysis, especially polyesterification and olefin polymerization (2) polymer cross-linking to enhance performance properties and (J) Surface modification for adhesion, lubricity, or pigment dispersion. 

Gelled Explosives. Aqueous solutions of water-dispersible, nonionic, natural hydroxylated polymers, such as galactomannans and their derivatives, can be cross-linked with organic titanates, such as TYZOR TE, TYZOR AA, and TYZOR LA to give water-bearing gels, which can be used to formgeUed explosives (532—534). 

Spherical, Fine-Particle Titanium Dioxide. Spherical, fine-particle titanium dioxide that has no agglomeration and of mono-dispersion can be manufactured by carrying out a gas-phase reaction between a tetraalkyl titanate vapor and methanol vapor in a carrier gas to form an initial fine particle, which can then be hydrolyzed with water or steam (572). 

Kohno, M., Kaneko, T., Ogura, S., Sato, K., Inoue, Y. 1998. Dispersion of ruthenium oxide on barium titanates (BasTij,0. , Ba.,Tij303, BaTi.,0, and BajTi,Oj, ) and photocatalytic activity for water decomposition. J Chem Soc Faraday Trans 94 89-94. 

These add to aldehydes providing the homoaldol products 351 with high stereoselectivity following the expected stereochemical course, as could be elucidated by several X-ray crystal structure analyses under anomalous dispersion (equation 93). It is currently unknown why the yields are relatively low (21-35%), since we could not detect side products besides traces of starting material. The corresponding lithium-TMEDA complexes, after titanation, deliver good yields (71-79%). The homoaldol products are easily converted to enantioenriched bicyclic y-lactones of type 352 °. 

Phases Identified in Ceramic Titanate Waste Energy Dispersive Analysis Ti... 

Uribe, R., Baudin, C. (2003), Influence of a dispersion of aluminum titanate particles of controlled size on the thermal shock resistance of alumina , 7. Am. Ceram. Soc., 86(5), 846-850. 

Ph. Ghosez, X. Gonze and J.-P. Michenaud, "Ab Initio phonon dispersion curves and interatomic force constants of barium titanate," accepted for publication in Ferroelectrics. 

The polymeric acyl titanate esters are viscous liquids or waxes that are soluble in hydrocarbon solvents and can be used as Ti02-dispersing agents, water-repellent agents for textile fabrics, and mst inhibitors for steel. 

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. 

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