Analysis of poly(ethylene oxide)-b-poly(propylene oxide) block copolymers by MALDI-TOF mass spectrometry using collision induced dissociation

Polyethylene oxide and polypropylene oxide homopolymers, blends and block copolymers were analyzed by collision-induced dissociation (CID) MALDI-TOF experiments. CID produced product ions that were specific for the monomer sequences in different oligomer molecules. By CID analysis of oligomer precursor ions with different monomer sequences and masses the degree of polymerization of the homopolymer sequences could be determined. MALDI-TOF-CID was not only selective towards the number and type of monomer units but also towards their sequence in the oligomer chain making it possible to differentiate diblock and triblock copolymer molecules.