INFLUENCE OF TACTICITY ON POLYMER SURFACES STUDIED BY TOF-SIMS

Poly(methylmethacrylate) (PMMA) and polystyrene (PS) thin films of dif ferent tacticities have been analysed by time-of-flight (ToF) SIMS in order to look for a possible influence of the stereoregularity on thei r fingerprint spectra (m/z less than or equal to 200). Because, at fir st glance, the spectra of samples with different tacticities seemed ra ther similar, the intensity ratios between secondary ions from main po lymer chain and those from pendant group were evaluated. By this proce dure, it was found that isotactic PMMA can be clearly distinguished fr om syndiotactic and atactic PMMA, A lower concentration of the methyl- methacrylate pendant group was detected at the surface of the isotacti c sample. In the case of PS, more phenyl groups were found to be prese nt at the surface of isotactic PS and an empirical criterion is propos ed to differentiate between atactic and isotactic PS.