Study on biodegradable polymer. 3. Synthesis and characterization of poly(DL-lactic acid)-co-poly(ethylene glycol)-co-poly(L-lysine) copolymer

The synthesis of poly(DL-lactic acid)-co-poly(ethylene glycol)-co-poly(L-lysine) copolymer was investigated by the reaction of amino acid-N-carboxy anhydride with lactic acid anhydrosulphite and methoxypolyoxyethylene amine (MPEG-NH2). The successful synthesis was obtained after adding dibutylmegnesium into the system. The product was proved to be copolymer. The solubility of the polymer revealed that it was ionic polymer. (C) 2002 Elsevier Science Ltd. All rights reserved.