Poly(poly(ethylene glycol)-co-L-aspartic acid) (PEG-ASP)n ahemating prepolymer was first prepared by the solution polycondensation from N-(benzyloxycarbonyl)-L-aspartic acid anhydride and poly(ethylene glycol)．Then

the novel PLGA-(PEG-ASP)n copolymers with pendant amine functional groups were synthesized by bulk ring-opening eopolymerization of D

L-LA with GA using tin octoate(Sn(Oct)2) as a catalyst

and (PEG-ASP)n prepolymer as a co-initiator．The structure and properties of the novel eopolymers were studied by GPC

FT-IR

1H-NMR and DSC

etc．Results showed that the PLGA-(PEG-ASP)n copolymers were typical amorphous polymers．The content of (PEG-ASP)n prepolymer had significant influence on the properties of the copolymers．The hydmphilieity of the eopolymers was improved and the value of the glass transition temperature(Tg) decreased as the content of the prepolymer increased．The benzyloxyearbonyl (CBz) protecting groups of the eopolymer were totally removed by catalytic transfer hydrogenation using palladium over activated carbon(5 wt％) as a catalyst and H2 as an effective hydrogen donor．The molecular welight

the value of Tg and hydrophilieity of the eopolymer were somewhat increased as the CBz protecting groups were removed．