Multiarm Star-Shaped Polydimethylsiloxanes with a Dendritic Branching Center

Molecules. 2021 May 29;26(11):3280. doi: 10.3390/molecules26113280.

Abstract

New multiarm stars have been synthesized based on polylithium derivatives of high-generation carbosilane dendrimers. In the synthesis of multiarm stars based on the eighth-generation dendrimer, steric hindrances were observed even during the synthesis of a polylithium initiator. Subsequently, this led to chain transfer reactions between growing arms, as well as other side effects. As a result, dense nanogel formations with a higher tendency of ordering than in classical objects of this type were isolated from the reaction mixture. The study of the rheology of multiarm stars based on sixth-generation dendrimers made it possible to determine the activation energies of viscous flow in these objects, which makes it possible to consider them as objects with a macromolecular nature and a reptation flow mechanism.

Keywords: anionic polymerization of hexamethylcyclotrisiloxane; carbosilane dendrimers; multiarm stars; polylithium initiator.