Carbosilane dendrimers with diundecylsilyl, diundecylsiloxane, and tetrasiloxane terminal groups: Synthesis and properties

Three derivatives of poly(allylcarbosilane) dendrimers of the fifth generation with different terminal groups are synthesized. The influence of terminal groups on the properties of the dendrimers in bulk and solution is investigated by viscometry, precision adiabatic vacuum and differential scanning calorimetry, dynamic light scattering, and atomic force microscopy. It is shown that the surface layers of the dendrimers substantially affect their properties and behavior. The existence of the second relaxation transition and its dependence on the nature and structure of terminal groups are established. The experimental data indirectly confirm the assumed formation of intermolecular entanglement networks for higher generation dendrimers.