RAFT 链转移剂的选用原则及通用型 RAFT 链转移剂

Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT Polymerization) is currently one of the most common “Reversible Deactivation Radical Polymerization”, and it has been widely used by scientists in different directions because of its advantages such as narrow molecular weight distribution, wide range of applicable monomers, and mild reaction conditions. However, when scientists choose RAFT chain transfer agents (also known as RAFT agents) in polymerization, they often donot clearly understand the principle of matching the activity of RAFT chain transfer agents and monomers. Therefore, in the preparation of block copolymers of “more activated” monomers (MAMs) and “less activated” monomers (LAMs), there are problems that the product has a wide molecular weight distribution, a slow polymerization rate, and even the reaction cannot successfully continue. Based on this, we first review the selection principles of RAFT chain transfer agents in polymerization, and then introduce the principle and application conditions of a universal RAFT chain transfer agent (Universal RAFT agent) (including non switchable type and proton switchable type) developed in recent years that is suitable for the polymerization of MAMs/ LAMs. Finally, the latest development and application of block copolymers with MAMs and LAMs based on Universal RAFT agents are discussed in depth.