Six new star-shaped polydimethylsiloxane (PDMS) with various cyclic siloxane cores were synthesized by the "grafting onto" method. The polymers obtained feature low dispersity and well-defined structures. Two of them, Q 8 -PDMS and D 12 -PDMS, have a three-dimensional spatial structure traditional for star-shaped polymers where the arms are arranged in all directions from the branching center. The other four polymers, D 4 -PDMS-D 8 -PDMS, have quite a different spatial geometry (cis-structure) where all the PDMS-arms are arranged on one side of the branching center plane. Such star-shaped structures were not reported before. The structures and purity of the polymers obtained were confirmed using a set of physicochemical methods of analysis. The effect of the macromolecule structure on the properties of the target polymers was identified.

New non-crystallizable low-dispersity star-shaped polydimethylsiloxanes (PDMS) containing stereoregular cis-tetra(organo)(dimethylsiloxy)cyclotetrasiloxanes containing methyl-, tolyl- and phenyl-substituents at silicon atoms and the mixture of four stereoisomers of tetra[phenyl(dimethylsiloxy)]cyclotetrasiloxane as the cores were synthesized. Their thermal and viscous properties were studied. All synthesized compounds were characterized by a complex of physicochemical analysis methods: nuclear magnetic resonance (NMR), FT-IR spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), viscometry in solution, rheometry, and Langmuir trough study.

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Wedge-shaped dendrons based on benzenesulfonic acid form a variaty of liquid crystal mesophases such as ordered and disordered columnar hexagonal, micellar cubic Pm3n etc. Among the factors affecting phase behavior...