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Metal alkoxides analysis

The process known as transimidization has been employed to functionalize polyimide oligomers, which were subsequentiy used to produce polyimide—titania hybrids (59). This technique resulted in the successhil synthesis of transparent hybrids composed of 18, 37, and 54% titania. The effect of metal alkoxide quantity, as well as the oligomer molecular weight and cure temperature, were evaluated using differential scanning calorimetry (dsc), thermogravimetric analysis (tga) and saxs. [Pg.330]

The ease of hydrolysis of metal alkoxides makes metal analysis a comparatively simple task. In many cases, the metal may be estimated by hydrolysis of a sample in a cmcible, and ignition to the metal oxide. Alternatively, the metal ion may be brought into solution by hydrolysis of a sample with dilute acid, followed by a standard analytical procedure for a solution of that particular metal. If the alcohol Hberated during the hydrolysis is likely to cause interference, it may be distilled from the solution by boiling. [Pg.28]

Monodisperse spherical oxide particles were prepared by the hydrolysis of metal alkoxide in homogeneous alcohol in an emulsion state. The formation mechanism from homogeneous alcohol and emulsion state was discussed by chronomal analysis and in situ observation using laser photo scattering. Two types of continuous systems for the industrial production of monodispersed oxide powders were also offered. [Pg.55]

G.C. analysis. All the samples have been identified by NMR, mass spectroscopy, I.R. and G.C. With this information in mind, it is believed that other systems, such as lithium morpholinide initiator, lithium morpholinide-metal alkoxide, etc., follow the same polymerization mechanism. [Pg.519]

As mentioned earlier, fairly successful conjectures (147, 148) about the structural features of homo- as well as heterometallic alkoxides were made earlier on the basis of physicochemical studies in solution. Even as late as 1989, Bradley (72) pointed out the special difficulties in the X-ray structural elucidation of metal alkoxide complexes. Such difficulties were reemphasized by Caul-ton and Hubert-Pfalzgraf (4), particularly the heterometallic alkoxides, which in many cases are obtained in a highly plastic (deformable) state even when crystallizable, which renders them unsuitable for single-crystal X-ray analysis. Therefore, the process of X-ray crystallographic structural characterization was gathering considerable momentum (4, 23, 28, 38, 39) and even with the availability of other more sophisticated techniques, publications were being limited mainly to derivatives characterized crystallographically. [Pg.277]

Chemical analysis of the lower molecular weight polymers produced by polymerization of epoxides with metal alkoxides in DMSO shows that sulfur is present [5] in low concentrations (< 0.4 percent) and this would arise from initiation involving DMSO, that is, pre-initiation [Eq. (10.17)] followed by ... [Pg.817]

The purity of metal alkoxide was established with the help of quantitative yield of compound and with microelemental analysis. [Pg.387]

For many years this moisture sensitivity of metal alkoxides cansed problems in the synthesis and characterization of pure metal alkoxides. Special techniques were developed for the elimination of water from reactants, solvents, and apparatus, thereby enabling not only the synthesis of metal alkoxides but also their characterization by infrared spectra, NMR spectra, mass spectra, and single-crystal X-ray diffraction analysis. [Pg.383]


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See also in sourсe #XX -- [ Pg.599 ]




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