Synthesis of well‐defined glycoconjugate polyacrylamides via preactivated polymers prepared by ATRP

Poly( N ‐acryloxysuccinimide) (polyNAS) with narrow molecular weight distributions (MWD) applicable for the preparation of well‐defined glycoconjugate polyacrylamides were successfully prepared by atom transfer radical polymerization (ATRP). The structures of polyNAS were characterized by 1 H‐NMR and GPC. GPC results showed that the molecular weight polydispersity indices (PDI) range from 1.17 to 1.29. The molecular weights could be calculated based on 1 H‐NMR results but GPC results of polyNAS by using 0.01 M LiBr/DMF did not give accurate molecular weights, probably because of the complex interaction in the system. The effects of free N ‐hydroxysuccimide produced in the polymerization processes on the free‐radical concentrations and apparent initiation efficiencies of ATRP were discussed. Well‐defined glycoconjugate polyacrylamides (i.e., with narrow molecular weight distributions and designed glycoconjugate degrees) were prepared by substituting N ‐oxysuccimide units with galactosamine followed by reaction of ethanolamine. The galactose conjugate degrees were determined by 1 H‐NMR and the total substitutions of N ‐oxysuccimides were verified by 1 H‐NMR and FTIR.