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Tetrabutyl Titanate (tetrabutyl + titanate)
Selected AbstractsPoly(ethylene terephthalate) recycling and recovery of pure terephthalic acid by alkaline hydrolysisADVANCES IN POLYMER TECHNOLOGY, Issue 4 2002G. P. Karayannidis Abstract Poly(ethylene terephthalate) (PET) taken from postconsumer soft-drink bottles was subjected to alkaline hydrolysis after cutting it into small pieces (flakes). The reaction took place in an autoclave at 120,200°C with aqueous NaOH solutions and at 110,120°C with a nonaqueous solution of KOH in methyl Cellosolve. The disodium or dipotassium terephthalate received was treated with sulfuric acid and terephthalic acid (TPA) of high purity was separated. The 1H NMR spectrum of the TPA revealed an about 2% admixture of isophthalic acid together with the pure 98% TPA. The purity of the TPA obtained was tested by determining its acidity and by polymerizing it with ethylene glycol by using tetrabutyl titanate as catalyst. A simple theoretical model was developed to describe the hydrolysis rate. The activation energy calculated was 99 kJ/mol. This method is very useful in recycling of PET bottles and other containers because nowadays TPA is replacing dimethyl terephthalate (the traditional monomer) as the main monomer in the industrial production of PET. © 2002 Wiley Periodicals, Inc. Adv Polym Techn 21: 250,259, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10029 [source] Stabilized dispersions of titania nanoparticles via a sol,gel process and applications in UV-curable hybrid systemsPOLYMER INTERNATIONAL, Issue 4 2006Xiahong Zhang Abstract Organic,inorganic hybrid UV-curable coatings were synthesized through blending UV-curable components and stabilized titania sol prepared via a sol,gel process of tetrabutyl titanate (TBT) with three different stabilizers, acetylacetone (Acac), isopropyl tri(dioctyl)pyrophosphato titanate coupling agent (TTPO) and a polymerizable organic phosphoric acid (MAP). The size and the dispersion of titania particle in the UV-cured organic matrix were dominated by the properties of these stabilizers. A cured hybrid film with titania particle size around 20 nm was obtained when TTPO was utilized as protection agent for the sol. It is interesting that the hardness and flexibility of the photocured hybrid films were improved simultaneously, in contrast to results with neat organic UV-curable formulations. Copyright © 2006 Society of Chemical Industry [source] Preparation of a Transparent Spherical Polymer Matrix Containing TiO2/SiO2 Hybrid MaterialsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 4 2008D.-H. Zhang Abstract A transparent spherical polymer matrix containing TiO2/SiO2 hybrid materials is prepared from the copolymerization reaction between TiO2/SiO2 hybrid materials containing vinyl groups and methyl methacrylate (MMA). Transparent TiO2/SiO2 hybrid materials are prepared from the reaction between nucleophilic agents and tetrabutyl titanate (TBT). Three reaction mechanisms leading to the formation of nanometer TiO2/SiO2 hybrid materials, including the single group coordination reaction mechanism (SGCRM), double group chelation reaction mechanism (DGCRM) and bridge coordination reaction mechanism (BCRM) are discussed in detail and confirmed by FT-IR spectroscopy. The sizes of the TiO2/SiO2 hybrid material nanoparticles are also characterized and calculated by TEM and range from 20,40,nm. The diameter of the particles in the transparent spherical polymer matrix is ca. 100,200,nm and their shape is a regular spherical structure from TEM observations. The transparent spherical polymer matrix containing TiO2/SiO2 hybrid materials could be used as holographic anti-counterfeiting materials. [source] Synthesis of Anatase TiO2 Nanoparticles with ,-Cyclodextrin as a Supramolecular ShellCHEMISTRY - AN ASIAN JOURNAL, Issue 5 2006Landong Li Abstract We report a novel, green hydrothermal-synthesis route to well-dispersed anatase TiO2 nanoparticles with particle sizes of 9,16,nm in the presence of ,-CD (,-cyclodextrin). During the synthesis process, the CD-containing synthesis mixture assembled in both longitudinal and latitudinal directions. Driven by the interaction between molecules, the ,-CDs assembled in the longitudinal direction to form long-chain compounds, whereas in the latitudinal direction, they tended to form regular aggregates through coordination with the Ti species from the hydrolysis of tetrabutyl titanate. In view of the effect of the coordination and the steric hindrance of ,-CDs as a supramolecular shell, homogeneous nuclei and slow growth of TiO2 crystals during the synthesis process was observed, which was responsible for the formation of uniform TiO2 nanoparticles. The low ,-CD dosage and the high product yield (>90,%) demonstrated well the potential of this synthesis route in the large-scale industrial production of anatase nanoparticles. [source] | ||||||||||