Synthesis and Characterization of Hyperbranched Polyacrylamide Using Semibatch Reversible Addition−Fragmentation Chain Transfer (RAFT) Polymerization

Hyperbranched polyacrylamides (b-PAM) were synthesized using a semibatch RAFT copolymerization of acrylamide (AM) and N,N ′-methylenebis(acrylamide) (BisAM) with continuous feeding of BisAM. Small amounts of chain transfer agent (CTA), 3-benzyltrithiocarbonyl propionic acid, with 1/20 to 1/50 molar ratios to BisAM were used to control gelation during the polymerization. Influences of BisAM addition rate, CTA to initiator molar ratio, and AM …