SURFACE STUDY OF POLYMERS BY STATIC SECONDARY-ION MASS-SPECTROMETRY USING A MAGNETIC-SECTOR MASS-SPECTROMETER

Results from static SIMS analysis of six thermoplastic polymers - poly tetrafluoroethylene (PTFE), polyethylene (PE), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polystyrene (PS) and polyca rbonate (PC) - using a magnetic-sector SIMS instrument and O2+ primary beam are presented. For PTFE as a representative sample, the charging effect is reduced only with a metal grid when analyzing positive seco ndary ions. When negative secondary ions are analyzed, excessive charg es are self-compensated with a normal-incidence electron gun. Positive -ion spectra collected agree with spectra obtained using either a quad rupole or time-of-flight SIMS instrument and noble-gas ion beams. The agreement is objectively demonstrated by means of the capability to co mpare spectra in the NIST/EPA/MSDC mass spectral database. The merits of the use of high-mass resolution, of which magnetic-sector SIMS is i nherently capable, to provide analytical information about the molecul ar species native to the sample are demonstrated in distinguishing thr ee ambiguous peaks with nominal mass ratios m/z = 27,39 and 59 from PM MA.