ИСТИНА

The study revealed that the polycondensation of stereoisomers in nonequilibrium conditions in absence of LAC results in production of the cage-like compounds. The equilibrium conditions of polycondensation lead to the appearance of a homologous series with defective cage-like structure. The polycondensation of stereoisomers [R(HO)SiO]4, where R=C6H5, m-CH3C6H4, m-ClC6H4 in the presence of LAC gives polymers with various structures: iso- , syndiotactic cyclolinear, columnar type and branched. The type of the structure unit depends on the structure of the initial stereoisomer. With the example of all cis- and cis-trans-cis [С6Н5(HO)SiO]4 isomers it was shown that starting cyclotetrasiloxanes conformation was inherited in the polycondensation reaction in the presence of montmorillonite with cyclolinear polyphenylsilsesquioxane obtained. The 29Si NMR and IR spectroscopy revealed the differences in the structure of cyclolinear polyorganosilsesquioxanes units which depend on whether they were synthesized by polycondensation of stereoisomers or by anion polymerization.