Dumbbell‐Shaped, Graft and Bottlebrush Polymers with All‐Siloxane Nature: Synthetic Methodology, Thermal, and Rheological Behavior

Abstract

A methodology for synthesizing a wide range of dumbbell‐shaped, graft and bottlebrush polymers with all‐siloxane nature (without carbosilane linkers) is suggested. These macroarchitectures are synthesized from SiOH‐containing compounds—silanol (Et3SiOH) and siloxanol dendrons of the first and second generations, with various peripheral substituents (Me or Et)—and from linear siloxanes comprising terminal and internal SiH groups by the Piers–Rubinsztajn reaction. Products and key building blocks are obtained in yields up to 95%. These polymers are heat and frost‐resistant siloxanes. As it turns out, the product physical properties are determined not only by the macromolecular structure, the linear chain length, the size and frequency of branched pendant, but also by the type of peripheral substituents—Me or Et—in the pendant. Thus, the viscosity of the graft polymers with branched pendant groups comprising peripheral Me‐groups is more than ≈3–5 fold lower than that of analogous polymers with peripheral Et‐groups.

Ionic Cyclopropenium-Derived Triplatinum Cluster Complex [(Ph3C3)2Pt3(MeCN)4]2+(BF4–)2: Synthesis, Structure, and Perspectives for Use as a Catalyst for Hydrosilylation Reactions

“…Detailed structural NMR studies − of complex A in a MeCN and chloroform solutions, in which it is well soluble and stable, show the complete identity of its structure with respect to the crystalline state. 1 H, 13 C, 19 F and 11 B NMR spectra show typical chemical shift values for similar types of structures (see the Supporting Information).…”

[M]-/Organo-Catalyzed Aerobic Functionalization of Alkylaryl-Siloxanes: Synthesis Carboxy-, Carbonyl- and Hydroxy-Aryl-Siloxanes

“…; in polymer chemistry and materials scienceas building blocks for obtaining well-defined https://doi.org/10.26434/chemrxiv-2024-l9j07 ORCID: https://orcid.org/0000-0003-4735-3666 Content not peer-reviewed by ChemRxiv. License: CC BY-NC-ND 4.0 macroarchitectures, [13] self-healing, [14] porous (MOFs, [15] HOFs, [16] COFs, [17] aerogels [18] ) and other multifunctional hybrid materials. Main area of application of silicones is paints, coatings, adhesives and sealants.…”

Tris(pentafluorophenyl)borane-catalyzed Hydride Transfer Reactions in Polysiloxane Chemistry—Piers–Rubinsztajn Reaction and Related Processes

“…Arzumanyan and co-workers prepared well-defined polysiloxanes of various architectures, including dumbbell-shaped and bottlebrushed ones, using TPFPB-promoted SiH + SiOH condensations of linear polydimethylsiloxanes with a Si-H terminal or internal groups with siloxanol-functional dendrons [ 133 ]. Scheme 45 illustrates examples of these syntheses.…”