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.