CHARACTERIZATION OF LOW-MOLECULAR-WEIGHT POLYMERS USING MATRIX-ASSISTED LASER-DESORPTION TIME-OF-FLIGHT MASS-SPECTROMETRY

Matrix assisted laser desorption/ionisation time-of-flight mass spectr ometry (MALDI-TOF MS) is used to mass characterise several low molecul ar weight, commercially available PS, PMMA and PEG samples. In additio n, the utility of the technique for the study of polymer synthesis is demonstrated; different initiation and termination mechanisms leave de ad chains with characteristic end groups which, in many cases, can be rapidly identified mass spectrometrically. There is broad agreement be tween MWDs derived from MALDI spectra and those obtained from conventi onal GPC analysis, but in some instances the differences are significa nt. Polydispersities obtained mass spectrometrically are invariably lo wer than those determined by GPC.