Analysis of Photoablation Products Resulting from Polymer Materials by Supersonic Beam/Multiphoton Ionization/Time-of-Flight Mass Spectrometry.

Photoablation products arising from polymer materials were examined by supersonic beam spectrometry, and the results are compared with those obtained by thermal decomposition. The high selectivity provided by supersonic beam spectrometry allows detection of minor species, e.g., styrene occurred from poly(α-methylstyrene) by cleavage of a methyl group and by proton rearrangement. Because ablation techniques involve high temperatures, thermally stable materials such as poly(p-methylstyrene) can be examined. The latter material is difficult to examine by thermal decomposition, even at 350 °C. It is also possible to differentiate between isomer ablation products, e.g., α-methylstyrene and p-methylstyrene. The instrumental setup described herein was used to examine several authentic samples, such as ABS resin (acrylonitrile-butadiene-styrene) and O-ring (SBR, styrene-butadiene rubber), as well as polystyrene foam. As a result, a styrene segment could be confirmed to be present in these materials. However, no evidence was found for its presence in a glue sample that was suspected to contain styrene on the basis of conventional mass spectrometry. The latter finding confirms the high degree of selectivity of the technique.