Synthesis and Characterization of Dye-labeled Copolymers by Reversible Addition-fragmentation Transfer (RAFT) Polymerization

Copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-hydroxysuccinimide methacrylate (NMS) were synthesized by reversible addition-fragmentation transfer (RAFT) polymerization using a semi-batch method. The copolymers were prepared in a wide range of molecular weights (Mn= 4,200-14,000 g/mol) with narrow polydispersities (1.2-1.4). A new approach was developed to prepare a modified RAFT chain transfer agent, a naphthalimide-dyelabeled dithiobenzoate. It was used to prepare a naphthalimide-dye end-labeled poly(HPMA-co-NMS). The copolymer was characterized by four different methods, 1H NMR spectroscopy via end group characterization and using 3-(trimethylsilyl)propionic acid-d4 sodium salt (TSP)external standard, end group analysis by UV-Vis spectroscopy and by GPC. The results obtained from these measurements are in good agreement.MAS