Studies On The Preparation And Degradation Of Polylactide/Poly-N-Vinylpyrrolidone Block Copolymers

Polylactide (PLA) and its copolymers are a kind of much better biocompatible and biodegradable polymers and are being increasingly used in medicine and organ fields. However, this kind of polymers is still limited in above applications due to its intrinsic hydrophobicity. In this paper, a novel amphiphilic block copolymers of poly-N-vinylpyrrolidone (PVP) and poly(D, L-lactide) were synthesized by atom transfer radical polymerization (ATRP). The degradated behaviours of copolymers were also studied in detail. The main conclusions can be drawn as follows:(l)Polylactide and hydroxyl-both terminated polylactide (HO-PLA-OH) were prepared by bulk melt polycondensation. The products were characterized by IR, ~1H-NMR and GPC. The results showed that the structure of two products was accord with designed structure. The molecular weight of HO-PLA-OH was high to 3700.(2)The functional macromolecular initiators (PLA-Br and Br-PLA-Br) were respectively prepared by reaction of polylactide or...