Synthesis of new functional hexamethyltrisiloxanes and telechelic polydimethylsiloxanes based on them

Abstract

Oligo-and polysiloxanes with terminal functional groups are of great interest in terms of syntheses of siloxane-containing block copolymers by various synthetic methods. In this study, synthesis of bifunctional di-and trisiloxanes with different terminal 4-(phenylene ethylene) substituents was developed using hydrosilylation under mild reaction conditions. Six new trisiloxanes with different functional substituents can be produced either directly by hydrosilylation of 4-substituted styrene derivatives or by consistent conversion of the homologues obtained. All the functional trisiloxanes synthesized are suitable as chain stoppers in the ring-opening polymerization of cyclosiloxanes. We believe that synthesis not only of symmetrical oligosiloxanes but also of asymmetrical hydrodosiloxane-containing analogues is a promising approach. Compounds of this kind will be in demand as precursors for the production of functional siloxane derivatives by the hydrosilylation reaction. Thus, symmetrical or asymmetrical telechelic oligo-or polydimethylsiloxanes with different functional groups are suitable as AA-type blocks for further synthesis of block copolymers.

Ring-Opening Polymerization (ROP) and Catalytic Rearrangement as a Way to Obtain Siloxane Mono- and Telechelics, as Well as Well-Organized Branching Centers: History and Prospects

“…The synthesis of not only symmetrical oligosiloxanes but also asymmetric hydridosiloxane-containing analogs has potential applications as precursors for the preparation of functional siloxane derivatives by the hydrosilylation reaction. Thus, symmetrical or asymmetric telechelic oligo-or polydimethylsiloxanes with different functional groups are suitable as AA-type blocks for further synthesis of block copolymers [107].…”

“…The synthesis of not only symmetrical oligosiloxanes but also asymmetric hydridosiloxane-containing analogs has potential applications as precursors for the preparation of functional siloxane derivatives by the hydrosilylation reaction. Thus, symmetrical or asymmetric telechelic oligo-or polydimethylsiloxanes with different functional groups are suitable as AA-type blocks for further synthesis of block copolymers [107]. Moving on nonequilibrium processes, it is worth noting the work of Fei H. F. et al [108], where they studied the anionic ring-opening polymerization of 1,3,5-tris(trifluoropropylmethyl)cyclotrisiloxane in bulk using dilithium diphenylsilanediolate as initiator (I); and N,N-dimethylformamide (DMF), bis(2-methoxyethyl)ether (Diglyme), and 1,2-dimethoxyethane (DME) as promoters (P) (Figure 19).…”