Phosphazene superbase catalyzed ring-opening polymerization of cyclotetrasiloxane toward copolysiloxanes with high diphenyl siloxane content

Abstract

PDMS-ran-PDPS copolysiloxanes with varying diphenyl siloxane contents (up to 64 mol%) are readily prepared by phosphazene catalyzed ROP.

Phosphazene/Lewis Acids as Highly Efficient Cooperative Catalyst for Synthesis of High‐Molecular‐Weight Polyesters by Ring‐Opening Alternating Copolymerization of Epoxide and Anhydride

“…TEB in tetrahydrofuran (THF) solution (1.0 mol L −1 ), triphenyl borane (TPB), and tris(pentafluorophenyl)borane (TFPB) were purchased from Sigma‐Aldrich and used without further purifications. CTPB was synthesized according to the procedure reported before 20e. All other chemicals were purchased from commercial suppliers and used without further purification unless otherwise noted.…”

“…Recently, our group developed cyclic trimeric phosphazene base ( CTPB , Scheme ) having the moderate basicity and a large spheric structure, which was highly efficient toward homopolymerization and copolymerization of various cyclic monomers . Particularly, the catalytic properties including activity and controllability can be facilely tuned by adding a second cocatalyst, such as urea or benzoic acid .…”

Synthesis of Diverse Polycarbonates by Organocatalytic Copolymerization of CO2 and Epoxides: From High Pressure and Temperature to Ambient Conditions

“…Phosphazenes have been widely used as organocatalysts for ring‐opening polymerizations, and the catalytic properties are greatly dependent upon their basicity and molecular structures [36] . Recently, three phosphazenes (CTPB, C 3 N 3 ‐Py‐P 3 and C 3 N 3 ‐Me‐P 3 as shown in Scheme 1) with tunable basicity and structures have been successfully developed in our group and showed high efficiency for ROPs of various cyclic monomers [55–63] . In this study, these phosphazenes in combination with TEB were tested as binary organocatalytic pair for copolymerization of CO 2 with different epoxides (Schemes 1 and 2) under various conditions.…”

Reprocessable Supramolecular Elastomers of Poly(Siloxane–Urethane) via Self‐Complementary Quadruple Hydrogen Bonding

“…[1][2][3][4] In particular, polydimethylsiloxane (PDMS) is praised for its excellent biocompatibility, high gas permeability, low glass transition temperature (T g ), low surface energy, good thermal and oxidative stability, and water repellency. [5][6][7][8] Over the past decade, supramolecular silicone materials [9,10] have attracted much attention due to their outstanding properties, such as high DOI: 10.1002/macp.202100116 stiffness, high stretchability, self-healing ability, and thermoplastic capacity. These unprecedented properties are attributed to the dynamic nature of supramolecular bonds, whose energies are low enough to allow bond exchanging under mild conditions.…”