Tetraisopropyl titanate, preparation

Compared with 49, 2,5-dioxabicyclo[2.2.2]octan-3-one (54) prepared from sodium 3,4-dihydro-2//-pyran-2-carboxylate has a much low polymerization reactivity [54] Lewis acids such as antimony pentachloride, phosphorus pentafluoride, and boron trifluoride etherate were not effective at all to initiate the polymerization of 54. Trifluoromethanesulfonic acid induced the polymerization of 54, but the yield and molecular weight of the polymer were low. Bicyclic lactone 54 was allowed to polymerize with anionic and coordination initiators such as butyl-lithium, lithiumbenzophenone ketyl, and tetraisopropyl titanate. However, the... 

Steps 2 and 3 contain empirical representations of the x-ray amorphous HTO material. Co, Mo, Pd, and NiMo HTO catalysts are prepared by similar procedures. Co, Ni, and Pd were exchanged using metal nitrates Mo was added by ammonium paramolybdate. HTO-Si support materials were made by adding tetraethyl orthosilicate to the tetraisopropyl titanate prior to addition of... 

The Phenolic Resins Modified with Titanium are Synthesized from a High Ortho Novolac Resin and Tetraisopropyl Titanate. The Phenolic Resin Modified with both Titanium and Silicon is Prepared from 2 Weight Percent Titanium Containing Phenolic Resin and Diphenylsilanediol. (Data from Ref.[l 80])... 

To determine the structure of the polyesters, they were hydrolyzed by refluxing in dilute, aqueous sodium hydroxide solution (Fig. 19). The mixture was acidified with Amberlyst-15 ion-exchange resin, and the water was removed in vacuo. For the polymer prepared from tetraisopropyl titanate (Tyzor TPT), the hydrolysis product was identified as hydroxy acid j. This result confirmed the work of Moore and Kelly.However, for the polymer prepared with triisobutyl aluminum as catalyst, hydrolysis gave a white solid. 

The surface oxide was prepared by impregnation of silica Aerosi1-200 (Sg i OO m /g), with a n-hexane solution of a Ti-alcoholate (tetraisopropyl-titanate, Ti(OPr ) from Tilcom, 15.9% Ti). The TiO percentage (by weight) used has been c.a. 12%. This value corresponds roughly to the amount required to form a monolayer of titania on this type of silica (14.7%, 5.5 Ti/nm ) and... 

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