Practical Chain‐End Reduction of Polymers Obtained with ATRP

Abstract

A practical and user-friendly strategy for the chain-end reduction of halogen terminated polymers that employs hydrogen gas and heterogeneous catalysis (palladium on carbon) is reported. Quantitative dehalogenation of a wide variety of monomer families (polystyrenes, polyacrylates, and polymethacrylates) with either chlorine or bromine chainends is observed. The utility of this chain-end reduction is further highlighted by mild reaction conditions, simple purification, and compatibility with a wide range of solvents.

Scalable synthesis of an architectural library of well‐defined poly(acrylic acid) derivatives: Role of structure on dispersant performance

“…S56 and S57). To negate any influence of chain‐ends, the bromide end‐groups were removed through a simple and quantitative hydrogenation protocol recently developed in our group . As detailed in the Supporting Information, full structural analysis of intermediate t ‐BA polymers was accomplished by 1 H NMR and GPC with PAA molecular weights calculated from the obtained DP n of the corresponding P( t ‐BA) derivatives (Table ).…”

Recent advances on synthesis and biomaterials applications of hyperbranched polymers

“…Both ATRP and RAFT techniques enable controlled synthesis, which can even be carried out in one‐pot but sequential monomer polymerizations for construction of hierarchal structures. Both thioester (Lee et al, 2017; Willcock & O'Reilly, 2010) and halide (Anastasaki, Willenbacher, Fleischmann, Gutekunst, & Hawker, 2017) terminated polymers can undergo transformation to functionalize, or inert (Chong, Moad, Rizzardo, & Thang, 2007; Gutekunst et al, 2017) chain ends. In addition to the use of vinyl‐containing inimer and transmer in radical‐based SCVP, other feed stocks are capable of forming hyperbranched polymers by ring‐opening polymerizations using acid or base catalysts.…”

Aqueous reverse iodine transfer polymerization of acrylic acid

“…Despite the industrial significance of PAA, the direct free‐radical polymerization (FRP) of AA and other carboxylic acid containing derivatives is challenging and often prone to significant chain‐transfer events, unwanted branching, and gelation. Controlled radical polymerization (CRP) techniques, such as nitroxide‐mediated polymerization, atom‐transfer radical polymerization (ATRP), and reversible addition‐fragmentation chain transfer (RAFT), developed to mitigate the deleterious side reactions of conventional FRP, can enable the preparation of well‐defined polymeric materials with predefined molar mass, dispersity ( Ð ), and chain‐end functionality . However, few studies have examined the direct CRP of AA under aqueous conditions .…”