Sequence Analysis of an Isocyanate Oligomer by MALDI-TOF Mass Spectrometry Using Collision Induced Dissociation

摘要

A TDI-MDI oligomer obtained by hydrolysis of a crosslinked polyurethane (PU) was analysed regarding the oligomer distribution by standard MALDI-TOF-MS and the monomer sequence in the different oligomers by collision induced dissociation (CID) experiments. The CID experiments produced product ions that were selective towards the monomer sequences in different oligomer molecules. By selecting suitable oligomer precursor ions with different monomer sequences out of the total oligomer distribution and conducting CID experiments, specific product mass peaks were identified that were characteristic for random and blocky monomer sequences. Therefore, a mass spectrometric method has become available for the important class of PUs that is not only selective towards the number and type of monomer units but also towards their sequence in the oligomer chain.