Organocatalyst for Ring‐Opening Polymerization of Cyclosiloxanes Toward Polysiloxanes

Polysiloxanes are the most significant silicon-containing polymers with alternately arranged silicon and oxygen atoms in their main chain. With the diversity of organic substituents, polysiloxanes have broad applications for their different physicochemical characteristics and operating temperature ranges. In this chapter, the synthetic methods of polysiloxanes are summarized, as well as the organocatalyzed synthesis of polysiloxanes with different substituents. Organocatalysts, such as phosphazene bases, guanidines, phosphorus ylides, and N-heterocyclic carbenes (NHCs), are discussed in detail about their catalytic performances toward the anionic ring-opening polymerization (ROP) of different cyclosiloxanes. Precise synthesis of polysiloxanes with different side chains and end groups mediated by different organocatalysts is presented. The relationship between the structure and the basicity of the organobases and their catalytic properties is also discussed.