The review presents schemes for obtaining homologous series of the linear α,ω-carbofunctional oligodimethylsiloxanes with the silicone chain length from 6 to 60 siloxane units containing carboxydecyl, aminopropyl and glycidoxypropyl groups at the chain ends allowing to obtain organosilicon surfactants with reproducible structure and properties. Data on the surfactant colloidchemical properties and kinetic regularities of styrene polymerization in their presence are provided. Systematic research of heterophase styrene polymerization kinetic regularities in the presence of water-insoluble α,ω-carbofunctional oligodimethylsiloxane allowed to formulate the fundamental differences of polymerization kinetic regularities from those observed in the presence of water-soluble surfactants. The mechanism of interfacial adsorption layers formation with water-insoluble α,ω-carbofunctional oligodimethylsiloxanes on the surface of monomer drops and polymer-monomeric particles was considered. This mechanism consists in the forced surfactant replacement by the formed polymer (because of their incompatibility) to the interfacial adsorption layer and in the formation of the surfactant supermolecular structures. The latter in total with the polymer provide its high durability.
Partial polycondensation of RSi(OMe) 3 (R = C 6 H 5 , CH 3 ) by the reaction with АсOH in the presence of HCl is studied. Oligoorganomethoxysiloxanes are obtained of the average composition [RSi(OMe)O] 4 , [RSi (OMe) 4/6 O 7/6 ] 6 , RSi(OMe) 0.5 O 1.25 ] 8 , and [RSi(OMe) 0.4 O 1.3 ] 10 . Using the method of 29 Si NMR spectroscopy they were shown to contain three types of structural fragments: RSi(OMe) 2 O-, RSiOMe(O-) 2 , RSi(O-) 3 . Based on the kinetic data, on the composition, properties, and the 29 Si NMR spectroscopy data of the products the conclusion is made that the obtained compounds have polycyclic structure with branched fragments. Using the GLC method the reaction was shown to have an induction period, whose duration can be substantially shortened by addition of HCl or methanol.Reactions of organoacetoxysilanes with alcohols [1, 2] and organoalkoxysilanes with organic acids [3][4][5][6][7][8][9][10][11][12][13] are an efficient method of synthesis of organosiloxanes of various composition and structure. A specific feature of these processes is the formation of the siloxane bond upon hydrolytic polycondensation in homogeneous environment due to the presence of water produced in the reaction of an acid with an alcohol. Thus, an industrial method for preparation of organosiloxane resins by the reaction of organoacetoxysilanes with methanol is described [1]. The synthesis of polyethylsiloxane liquids by the reaction of diethyldiethoxysilane with organic mono-and dicarboxylic acids in the presence of sulfuric acid as a catalyst is also described [3]. Depending on the ratio of the reagents cyclic or linear diethylsiloxanes can be obtained in quantitative yield. It was shown that carrying out the reaction of organoalkoxysilanes with acetic acid allows to substantially improve the control of the process, first of all as far as the control of the structure of the formed products is concerned [4]. This is connected with the fact that acetic acid and alcohol are an active medium of the reaction, which dissolve the reagents, the products, and are co-reagents.In the present work, we have investigated the partial polycondensation of phenyl-and methyltrimethoxysilanes RSi(OMe) 3 in the reaction with acetic acid in the presence of hydrogen chloride at different molar ratios of АсOH and RSi(OMe) 3 . The scheme of the reaction can be represented as follows [Eq. (1)].
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