Application of Controlled Radical Polymerization in the Development of Polymers with Branched Architectures

Various synthetic methodologies for preparation of functional polymers with branched architectures by using atom transfer radical polymerization (ATRP) of AB* inimers (containing initiator fragment B* and monomer vinyl group A in one molecule) and reversible addition-fragmentation chain transfer (RAFT) polymerization of polymerizable chain transfer agents (transmers) are discussed. The target of this body research is mainly focused on development of new methodologies for synthesis of hyperbranched polymers and hyperbranched-star (hyperstar) polymers with controlled structures and site-specific functionalities via controlled radical polymerization (CRP) techniques. The main tools used to achieve this goal include controlled radical self-condensing vinyl polymerization (SCVP) and chain extension polymerization in solution and heterogeneous microemulsion and seeded emulsion. Research progress on the use of radical polymerization to introduce branching points into polymers via CRP methods is discussed in the introductory chapter. Chapter 2 describes the application of microemulsion and seeded emulsion to produce core-shell structured hyperstar polymers in a one-pot process with activators generated by electron transfer (AGET) ATRP technique without worrying about the hyperstar-hyperstar coupling reactions. Chapter 3 presents the synthesis of high-molecular-weight hyperbranched polymers (M_n ~10⁶) via RAFT polymerization through copper-catalyzed trithiocarbonate transmer. Chapter 4 discusses a facile approach for successful synthesis of hyperbranched polymers with high molecular weight and uniform structure by a one-pot polymerization of transmers initiated using copper catalyst in a microemulsion.