Star‐shaped siloxane polymers with various cyclic cores: Synthesis and properties

Abstract

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.

Star-Shaped Polydimethylsiloxanes with Organocyclotetrasilsesquioxane Branching-Out Centers: Synthesis and Properties

“…According to DSC data obtained, full suppression of PDMS-arm crystallization process is observed in all SSPs. Similarly, crystallization of side chains was not observed for SSPs with 21 PDMS units per arm [44].…”

“…By using this method, we synthesized a series of low dispersity polydimethylsiloxane SSPs. Their molecules contain flexible stereoregular phenylcyclosilsesquioxanes [PhSi(O)OSiMe 2 H] n of various sizes, structures, and functionality (n = 4, 5,6,8,12), such as the branching center (core), as well as the cage octahedral silsesquioxane playing the role of rigid point center [43,44]. It should be noted that only two of six obtained polymers had three-dimensional spatial structures, traditional for SSP, in which the arms spread in all directions from the branching center.…”

Polyphenylsilsesquioxanes. New structures–new properties

“…104 Functional stereoregular macrocycles are in great demand for the synthesis of numerous derivatives. 105 In fact, they became a versatile multipurpose platform for synthesizing new polymeric forms, for example, star-shaped polymers 106,107 and analogs of calixarenes. 108 Some hydroxy derivatives of macrocycles exhibit the properties of plastic crystals due to a specic organization of hydrogen bonds.…”

Siloxanes—Versatile Materials for Surface Functionalisation and Graft Copolymers

“…A series of star-shaped PDMS derivatives was produced via the “grafting onto” method, utilising various siloxane-derived cores ( Figure 14 ) [ 36 ]. Vinyl-terminated PDMS arms with a narrow molecular mass distribution [polydispersity index (PDI) = 1.13] were synthesised via a living anionic polymerization.…”