ИСТИНА

To explore the inductive and steric influence of the substituents Si-atoms in organocyclotetrasiloxanes on the process of intercalation at the layered-architecture silicate Na+ MMT (montmorillonite) galleries in the reaction of polycondensation, we have synthesized all-cis-(tetrahydroxy)(tetra-m-tolyl)- (1) and cis-trans-cis-(tetrahydroxy)(tetra-m-chlorophenyl)-cyclosiloxane isomers (2) by hydrolytic polycondensation of m-tolyl- and m–chlorophenyltrichlorosilanes. By polycondensation of isomers 1 and 2 in the presence of montmorillonite in the solution of toluene, anisole at the temperature of 110–140o C, cyclolinear polyorganosil-sesquioxanes (3, 4) with the interchain distance of 13.2–13.5Ǻ were obtained. This suggests that besides phenyl other substituents with the increased Van-der-Waals volume can be used. The structure of 3 and 4 polymer units was confirmed by 29Si NMR, IR spectroscopy, powder X-ray diffraction, viscosimetry, and GPC. In the 29Si NMR spectra of the 3,4 polymers is present at 78.0  80.0 ppm singlet with a narrow maximum in contrast to polyorganosilsesquioxanes obtained by anionic polymerization of oligomeric prepolymers m-tolyl - and m-chlorophenyl--(hydroxycyclosiloxanes.