Automated synthesis of star-shaped block copolymers based on an 5-arm star poly(ethylene glycol) macro initiator

An example of a controlled living polymn. is the ring opening polymn. of lactides and lactones. This polymn. can be co-initiated by R-OH or R-NH2 functional groups, which open the ring monomers by a nucleophilic attack at the carbonyl C-atom. This results in a new R-OH functional group at the chain end of the oligomer/polymer, which can act as new co-initiator and propagation is achieved. In this study, we investigated the ring opening polymn. of lactides and lactones utilizing an automated synthesizer. Hereby, block copolymers with different mol. wts. were synthesized automatically and the reactions were monitored online by GPC to investigate the living character and the reproducibility of the polymns. carried out by the robot