Metal-containing polymers, studies

Why is there interest in the synthesis and study of metal-containing polymers ... 

Template Polymers. Template effects in chelating polymers constitute an interesting development in the field of metal containing polymers. The Template effects are interpreted by the fact that the small molecule is templating a pattern in the macromolecule which can be recognized by the same molecule in a subsequent process. The idea is to prepare a polymer from the metal-chelated monomer, to remove the metal ion, and then to measure the selectivity of the prepared polymer for the metal ion of the template [36]. Typical examples of template systems are 4-vinyl-4 -methylbipyridine (Neckers [36]) and 1-vinyl-imidazole (Tsuchida [37]). These are polymerized in presence of divinylbenzene [36] and appropriate metal salts (Co2+, Cu2+, Ni2+, Zn2+). The template metal ions are removed by acid leaching and the polymer subsequently used for metal ion absorption studies (Fig. 16). 

CoCp unit C-C bond activation, 7, 80 GoCp unit CH activation, 7, 79 in ethylene polymerization, 7, 81 substituted Cp, 7, 71 synthetic applications, 7, 77 tripodal rotations, dynamic NMR studies, 1, 415 7i-Cyclopentadienyl ligands, in metal-containing polymers,... 

Few definitive thermal studies of metal-containing polymers (with the exception of silicon-containing polymers) exist in the literature. Thermal analysis is typically done as a matter of preliminary testing on new polymers. Further, most of the studies were done prior to the advent of the automatic, programmed thennal analysis instruments. 

The technology of plasma formation of metal-containing polymers in the form of thin films dates from 1963, when Bradley and Hammes(15) prepared specimens from some forty different materials, and studied their electrical conductivities. Included in the study were organic compounds of iron, tin, titanium, mercury, selenium, and arsenic. The presence of a metal or transition element in the polymer did not lead to special electrical properties compared to the purely organic polymers studied. 

For the selective separation of organic compounds, specially prepared metal salt adsorbents (e.g., copper salts) are used, after volatile components have been eluted from them [106—108]. Good separations on these columns were obtained for isomeric ketones for example, heptanone-2, heptanone-3 and heptanone-4 were separated. Delventhal et al. [109] proposed the use of metal-containing polymers for the separation of various amines and thiophene. The advantage of these stationary phases was stated to be their high chemical and thermal stability. Nawrocki et al. [156] studied the application of coordination polymers as adsorbents and LSPs in GC. 

Metal-containing polymers containing the M—O and M—O—R moiety are synthesized with oxygen-containing chelating agents. These are considered in 15.2.15 and are reviewed in refs 4-6. Other studies also have appeared " . 

The biocidal properties of most metal-containing polymers have not been studied in detail. The biological activity of organotin polymers and copolymers to various fungi and microorganisms has been found only recently. 

This survey of synthetic routes to metallopolymers completes the discussion of introductory topics in this chapter. In the following chapters, the main classes of metal-containing polymers will be discussed, with emphasis not only on synthetic details, but also on their properties and applications. The general philosophy will be to focus on well-characterized and well-studied materials which are truly polymeric in nature (Mn> 10,000, see section 1.2.3) rather than to exhaustively discuss every metallopolymer mentioned in the literature. Particular attention is given to examples where studies of properties and potential functions have been performed. 

Polymers containing Hf(TV) in the main chain or side chains can be prepared by any of the known processes for synthesis of metal-containing polymers. An attractive approach is the polycondensation of dicyclo-pentadienyl derivatives of hafnium(IV) with diols or oxygen-free diacetylenic hgands. An alternative approach is polymerization of the Hf(TV) monomers with (meth)acrylate and fumarate groups, synthesized for the first time in this study. We investigated the thermolysis of the synthesized... 

Further, the thermogravimetric analysis of metal diols of HBP and respective metal-containing polymers was done to study the thermal stability of the polyesters. The TG data show that all the polyesters are very stable up to 250°C. The energies of activation of degradation of these polyesters have been calculated using the Fuoss method [106]. 

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