Reversible Deactivation Radical Polymerization: State-of-the-Art in 2017

Abstract

This chapter highlights the current advancements in reversible-deactivation radical polymerization (RDRP) with a specific focus on atom transfer radical polymerization (ATRP). The chapter begins with highlighting the termination pathways for acrylates radicals that were recently explored via RDRP techniques. This led to a better understanding of the catalytic radical termination (CRT) in ATRP for acrylate radicals. The designed new ligands for ATRP also enabled the suppression of CRT and increased chain end functionality. In addition, further mechanistic understandings of SARA-ATRP with Cu 0 activation and comproportionation were studied using model reactions with different ligands and alkyl halide initiators. Another focus of RDRP in recent years has been on systems that are regulated by external stimuli such as light, electricity, mechanical forces and chemical redox reactions. Recent advancements made in RDRP in the field of complex polymeric architectures, organic-inorganic hybrid materials and bioconjugates have also been summarized.

Atom Transfer Radical Polymerization for Biorelated Hybrid Materials

“…The advent and recent developments in the field of controlled radical polymerization during the past three decades have revolutionized the field of polymer science and its integration with biology. , Unlike conventional radical polymerization (RP) with no control over the molecular weight (MW) and molecular weight distribution (MWD) of the obtained polymers due to slow initiation, fast termination, and a short lifetime (∼1 s) of the propagating radical, RDRP methods provide fast initiation, diminished termination, and extension of the lifetime of growing chains to hours or even days. This is achieved through the introduction of a dynamic equilibria between the propagating radicals and dormant species that can be intermittently reactivated to reform the growing radical chain ends. , Chain ends can be easily extended to prepare block copolymers as well as construct polymers with complex architecture such as stars or bottlebrushes. − These systems have opened new avenues to prepare advanced materials with precise control over their compositions, architectures, and functional properties.…”

PET-RAFT Polymerization: Mechanistic Perspectives for Future Materials

“…First developed by Rizzardo and co-workers in 1998, reversible addition–fragmentation chain transfer polymerization (RAFT) has become one of the most versatile polymerization techniques, used in a wide range of polymer synthesis applications. RAFT polymerization is in the family of reversible deactivation radical polymerization (RDRP) methods. , This class of polymerization techniques includes other well-explored systems such as atom transfer radical polymerization (ATRP) , and nitroxide-mediated polymerization (NMP), as well as RAFT. RDRP techniques have received significant interest due to their ability to create well-defined polymers with predictable chain lengths and low dispersity ( Đ ), as well as “livingness”, giving continued chain growth. ,, RAFT in particular is of interest due to its ease of use and functional group tolerance .…”

“…RAFT polymerization is in the family of reversible deactivation radical polymerization (RDRP) methods. , This class of polymerization techniques includes other well-explored systems such as atom transfer radical polymerization (ATRP) , and nitroxide-mediated polymerization (NMP), as well as RAFT. RDRP techniques have received significant interest due to their ability to create well-defined polymers with predictable chain lengths and low dispersity ( Đ ), as well as “livingness”, giving continued chain growth. ,, RAFT in particular is of interest due to its ease of use and functional group tolerance . Though there are many benefits to RAFT, it is not a perfect process.…”

“…RDRP techniques have received significant interest due to their ability to create well-defined polymers with predictable chain lengths and low dispersity (Đ), as well as "livingness", giving continued chain growth. 4,7,8 RAFT in particular is of interest due to its ease of use and functional group tolerance. 9 Though there are many benefits to RAFT, it is not a perfect process.…”

Polymerization of Vinyl Chloride at Ambient Temperature Using Macromolecular Design via the Interchange of Xanthate: Kinetic and Computational Studies

“…Poly­(vinyl chloride) (PVC) is one of the most consumed polymers worldwide (more than 40 million tons per year) and is used to produce many items, namely, healthcare devices . The strong need for new polymers having different architectures, morphologies, controlled molecular weights, and functional chain-ends resulted in the unprecedented interest of the scientific community in reversible deactivation radical polymerization (RDRP). − RDRP offers a control over structure that is similar to ionic living polymerizations but with all of the advantages associated with radical-based polymerizations . Despite all of the achievements, the RDRP of nonactivated monomers, such as vinyl chloride (VC), remains enormously challenging due to the low reactivity of the VC monomer and the very high reactivity of the corresponding radical, an unusually high chain transfer constant to the monomer; and the insolubility of PVC in its monomer as well as in most common organic solvents. − …”