Static Secondary Ion Mass Spectrometry Analysis of UV Photopolymerization in Diacetylene Thin Films

The goal of this study is to use polymerization of Langmuir-Blodgett (L-B) films to model cross-linking at a polymer surface. Reported in this paper is the application of a quantitative method of static secondary ion mass spectrometry (SIMS) to evaluate the extent of UV-induced photochemical polymerization in diacetylene L-B films. Static SIMS provides a means to monitor the early stages of reaction. Pseudo-first-order rate constants are reported from the loss of monomer signal. These are consistent for the analysis of the loss of intensity of molecular ion and two daughter ions. These data are used to measure the extent of polymerization. Analysis of the quantitative data suggests that the early stages of polymerization occur at a much faster rate than the later stages.