Matrix‐assisted laser desorption ionization time of flight mass spectrometry analysis of living cationic polymerization of vinyl ethers. I. Optimization of measurement conditions for poly(isobutyl vinyl ether)

Matrix‐assisted laser desorption ionization time of flight mass spectrometry (MALDI‐TOF‐MS) was utilized for the analysis of polymers obtained by the living cationic polymerization of isobutyl vinyl ether (IBVE) with the HCl‐VE adduct/SnCl₄/n‐Bu₄NCl initiating system in CH₂Cl₂ at −78 °C. Under optimized analysis conditions, well‐resolved spectra were obtained for samples with number‐average molecular weights of ≤10⁴ with the use of 1,8‐dihydroxy‐9(10H)‐anthracenone (dithranol) as a matrix and sodium trifluoroacetate as an added salt. The MS spectra showed only one series of peaks separated exactly by the mass of the IBVE. The observed mass of each peak was in good agreement with the theoretical one, which possesses one initiator fragment at the α end and one methoxy group originated from quenching with methanol at the ω end. Thus, detailed end group analysis is possible for poly(VE). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4023–4031, 2000