Reaction Mechanism for the Hydrolysis of Titanium Alkoxides

doi:10.5012/bkcs.2003.24.5.671

Cited by 14 publications

(2 citation statements)

References 10 publications

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“…Removing isopropanol under a nitrogen flow or with vacuum displaces this equilibrium and drives the mechanism toward ketimine formation. The monohydroxy titanate obtained reacts immediately with a second molecule of titanium(IV) isopropoxide to afford a dimeric product and isopropanol …”

mentioning

confidence: 99%

Improved Process for Preparation of tert-Butanesulfinyl Ketimines of Hindered Ketones under Nitrogen Flow

Tabet

Rodeville

Boiteau

et al. 2016

Org. Process Res. Dev.

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An improved process for tert-butanesulfinyl ketimines formation using titanium(IV) alkoxides is described. This new protocol gives better results especially for sterically hindered ketones compared to classical conditions where titanium(IV) isopropoxide is found to be only moderately effective. We found that removal of isopropanol or ethanol from the reaction mixture either under a nitrogen flow or under vacuum dramatically increased reaction rate, extent of conversion, and yield of the reaction. This methodology has been exemplified on several substrates reported in the literature to be difficult.

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mentioning

confidence: 99%

Improved Process for Preparation of tert-Butanesulfinyl Ketimines of Hindered Ketones under Nitrogen Flow

Tabet

Rodeville

Boiteau

et al. 2016

Org. Process Res. Dev.

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“…However, the published kinetics for TBUT indicate an induction time which is three to four orders of magnitude longer than that for TTIP. An estimation of induction time for the perfectly mixed reactants, under consideration of the Arrhenius equation based on the data obtained by Park et al [64] (for further information please refer to SI, Eqs. ( 3)-( 6), Table 1), but neglecting the pH influence, results in induction times of 33 s and 657 s for TTIP and TBUT as precursors respectively.…”

Section: Mixing Simulation In the Lh2 Slit Plate Micromixermentioning

confidence: 99%

Towards process intensification: Remediation of fouling in continuous microscale synthesis of phosphated TiO 2

Hochstrasser

Jussen

Riedlberger

2017

Chemical Engineering and Processing: Process Intensification

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The use of continuous flow microreactors offers an interesting approach among the process intensification tools available. Fouling in a microreactor during synthesis of industrially relevant nanoparticles was investigated. In order to achieve this, microscale synthesis of phosphated TiO 2 nanoparticles from titanium(IV) isopropoxide (TTIP) and titanium(IV) butoxide (TBUT) was employed. A continuous three step process, consisting of hydrolysis of the respective alkoxide, phosphate modification and precipitation was developed. The resulting catalyst was characterized by means of nitrogen adsorption, dynamic light scattering and SEM/EDX. It was observed that TTIP resulted in massive fouling, while a stable process was possible with TBUT. This was related to the nucleation time of the particles. The particle size directly after the critical hydrolysis step was investigated. The particles formed with TTIP as a precursor (3.4 nm) were larger than those obtained from TBUT (2.4 nm). Diffusion based reactant concentration gradients within the multilamellar micromixer were calculated, and the corresponding Damköhler numbers for mixing were estimated to be 2.6•10 −3 for TBUT and 3.5•10 −2 for TTIP respectively. These numbers highlight the influence of incomplete mixing on fouling for TTIP as a precursor. Thus, our work demonstrates the necessity to consider the reaction kinetics during process intensification by miniaturization.

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Average mixing torque, tensile and impact properties, and thermal stability of poly(vinyl chloride)/sawdust composites with different silane coupling agents

Sombatsompop

Chaochanchaikul

2005

J of Applied Polymer Sci

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Unique explanations are given to describe changes in the mixing torque and tensile and impact properties of poly(vinyl chloride) (PVC)/wood sawdust composites affected by various types and concentrations of silane coupling agents. Concentrations of 0.5-1.0 and 1.5 wt % coupling agent are recommended for the optimization of the tensile and impact properties of the composites, respectively. Changes in the tensile and impact properties of the composites with a low sawdust content were more sensitive to the addition of silane coupling agents than those with a high sawdust content. KBM603 was suitable for improving the tensile properties, whereas KBE603 is recommended for high impact resistance of the composites. The differences in the mechanical and thermal properties of the PVC/sawdust composites were dependent on the characteristics of the functional groups in the silane coupling agents used, such as hydrophilic level, number of functional groups, self-condensation reaction, and effectiveness of the hydrolysis reaction. Silane coupling agents above 1.0 wt % resulted in an increase in polyene sequences in the PVC structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: [213][214][215][216][217][218][219][220][221] 2005

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Reaction Mechanism for the Hydrolysis of Titanium Alkoxides

Cited by 14 publications

References 10 publications

Improved Process for Preparation of tert-Butanesulfinyl Ketimines of Hindered Ketones under Nitrogen Flow

Improved Process for Preparation of tert-Butanesulfinyl Ketimines of Hindered Ketones under Nitrogen Flow

Towards process intensification: Remediation of fouling in continuous microscale synthesis of phosphated TiO 2

Average mixing torque, tensile and impact properties, and thermal stability of poly(vinyl chloride)/sawdust composites with different silane coupling agents

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