Characterization of Polystyrenes (1 kDa) Functionalized With and Without a Perfluorinated Endgroup by TOF-SIMS: Observation of Intact Oligomers and Endgroup Effects

Abstract

TOF-SIMS measurements of 1 kDa polystyrene functionalized with a perfluoroalkyl endgroup are presented. Intact oligomer signals in the high mass range and fragment signals in the low mass range are observed (monolayer sample preparation on a silver substrate). The successful functionalization of the polystyrene with the perfluoroalkyl endgroup can be confirmed by the masses at which the intact oligomer signals arise. The high mass region of the spectrum is compared to TOF-SIMS measurements of polystyrene with a proton endgroup. The signal for a polystyrene oligomer with a proton endgroup with a specific degree of polymerization (n) arises at a lower mass because of the absence of the perfluoroalkyl endgroup. The effect of endgroup on the ion transformation probability of intact oligomers is demonstrated in a TOF-SIMS spectrum of a physical mixture (1:1 mole ratio) of polystyrene with a proton endgroup and polystyrene with a perfluoroalkyl endgroup.