Organosilicon linear polymer with

Tebeneva, N. A. Rebrov, E. A. Muzafarov, A. M. Synthesis of Organosilicon Linear Polymer with Octaorganooctasilsesquioxanes Structural Units in Main Chain. In Silicones and Silicone-Modified Materials Clarson, S. J., Fitzgerald, J. J., Owen, M. J., Smith, S. D., Eds. AGS Symposium Series 729 American Chemical Society Washington, DC, 2000 pp 214-225. 

Synthesis of Organosilicon Linear Polymer with Octaorganooctasilsesquioxanes Structural Units in Main Chain... 

Oddly enough, Kipping had not been concerned primarily with the organosilicon polymers for which his work may best be remembered. He and his students had been interested principally in the preparation and characterization of new compounds, and in the study of their reactions. From such reactions they strove to isolate pure compounds as products, but in certain hydrolytic reactions they constantly were troubled by the appearance of oily or gluelike substances which could not be crystallized and which acted like very complex mixtures when subjected to fractionation procedures. It now seems surprising that they were able to isolate as many of the simpler cyclic and linear polymers as they did, considering the annoying qualities of the resinous masses. 

Hydrosilylation of unsaturated organosilicon compounds has also found several applications in molecular and polymer organosilicon chemistry. In particular, the addition of polyfunctional silicon hydrides to poly(vinyl)organosiloxane, catalyzed exclusively by Pt compounds and providing an activated cure for silicon rubber [10], has been of great practical importance. Hydrosilylation of the vinyl group at silicon seems to be effective synthetic method for preparation of oligomers and polymers with a linear or cyclolinear stmcture (polyhydrosilylation), and can occur either via the addition of dihydro-carbosilanes and -siloxanes to divinyl-silanes and -siloxanes [25, 26] or by intermolecular hydrosilylation [4] (eq. (1)). 

TABLE 1. Polymerization of dicyclopentadiene to linear polymer, in the presence of WCl6 and WOCI4 associated with organosilicon compounds ... 

Organosilicone surfactants can be classified according to the position of the lyophilic moiety with respect to the Si-O-Si polymer. The abbreviations M, D, T and Q, referring to the number of oxygen atoms bonded to the silicon, are used to define the silicone portion as shown in Table 2.8.2. Insertion of the lyophilic moiety (A) into the silicone polymer itself leads to monofunctional, i.e. M(D A)M, and polyfunctional linear, i.e. MID A D M, type surfactants. Polyfunctional linear versions are also described as rake, comb- or graft-copolymers. Substitution at the ends of the silicone polymer yields surfactants... 

The most effective method of modification of linear organosilicon polymers is the insertion of various elements or groups with a different chemical nature into the structure of the macromolecular chain. As a result of the insertion in the dimethylsiloxane chain of different fragments there are changes in the physical chemical properties [5]. The insertion of the cyclic fragments in the main linear dimethylsiloxane chain hinder the chain transfer reactions, which proceed with the release of D -type (where D = Me2SiO) cycles during the thermal depolymerisation, that raises the thermal-oxidative stability of the polymers [6]. 

A variety of linear organosilicon polymers having a thienylene unit in their backbone have been synthesized. We and Weber et al. have reported that the condensation reactions of 2,5-bis(chlorosilyl)thio-phenes with sodium metal afford thienylene-containing organosilicon polymers, poly[(disilanylene)-2,5-... 

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