Molecular level structure of novel synthetic analogues of aliphatic biopolyesters as revealed by multistage mass spectrometry

The present study focuses on electrospray ionisation (ESI) tandem mass spectrometry of novel copolyesters obtained by anionic ring-opening copolymerisation of β-substituted β-lactones. Detailed analysis of these copolyesters, including molecular chain architecture as well as the structures of the end groups, was performed using ESI-MS/MS collision-induced dissociation spectra. The random arrangement of comonomeric units along the copolyester chains was demonstrated by comparison of ESI-MSⁿ fragmentation spectra and fragmentation pathways. Sequence distribution analysis of comonomeric units confirmed the copolymer's random structure. ESI-MSⁿ proved to be a promising technique for structural analysis of copolyesters obtained via anionic ROP.