Synthesis of Novel Amphiphilic Block Copolymers of Poly-N-vinylpyrrolidone and Poly (D, L-lactide) by Atom Transfer Radical Polymerization
In order to improve the hydrophilicity of poly (D,L-latide) (PDLLA), a novel amphiphilic ABA-type triblock copolymers of poly-N-vinylpyrrolidone (A) and poly (D, L-lactide) (B), were successfully synthesized by atom transfer radical polymerization (ATRP) using N-vinylpyrrolidone (VP) as monomer, bromide-terminated poly (D,L-latide) oligomer (Br-PDLLA-Br) as functional macromolecular initiator which was prepared when hydroxy-terminated poly(D,L-latide) oligomer (HO-PDLLA-OH) reacted with 2-bromopropanoyl bromide, CuBr/2,2’-bipyridine complex as the catalyst system. The resulting copolymers were characterized by various analytical techniques. The results showed that the introduction of poly (N-vinylpyrrolidone) (PVP) segments into polylactide enhanced the surface hydrophilicity of the copolymers remarkably and amphiphilic polymer can self-assemble into core-shell structure (polymer micelle) in water by the balance of the hydrophilic and hydrophobic interaction.
Masayuki Nogami, Riguang Jin, Toshihiro Kasuga and Wantai Yang
S. X. Shi et al., "Synthesis of Novel Amphiphilic Block Copolymers of Poly-N-vinylpyrrolidone and Poly (D, L-lactide) by Atom Transfer Radical Polymerization", Advanced Materials Research, Vols. 11-12, pp. 461-464, 2006