Synthesis and AIE properties of PEG–PLA–PMPC based triblock amphiphilic biodegradable polymers

Using a O,N,N,O-tetradentate Salan yttrium alkyl complex as the precursor and monohydric PEG as the chain transfer agent, rac-LA and MPC monomers were sequentially ring-opening polymerized via living immortal mode to give biodegradable triblock amphiphilic copolymers of (PEG-b-PLA-b-PMPC) (PEG = poly(ethylene glycol) and MPC = 5-methyl-5-propargyloxycarbonyl-propylene carbonate). The subsequent “click” reaction between the azide functionalized AIE fragment tetraphenylethylene TPE-N3 and the alkyne substituent on the PMPC block provided swiftly the first AIE functionalized biodegradable amphiphilic copolymers. These copolymers self-assembled into homogeneous micelles that exhibited a tailored PL intensity and fine AIE performance, and should be attractive candidates for bioimaging and chemosensor applications.