Monitoring Degree of Cure and Coating Thickness of Photocurable Resins Using Fluorescence Probe Techniques

摘要

In this paper, we report recent progress in developing fluorescence probe technology for photocurable coatings. Intramolecular charge transfer (ICT) fluorescence probes based on derivatives of dansyl amide were found to be useful for monitoring cure of various photocurable resins the polymerization of which was initiated with UV or visible initiators. Fluorescence emission spectra of chosen ICT probes exhibited spectral blue shifts due to the increases in microviscosity surrounding the probe molecules as the photocuring process proceeded. A fluorescence intensity ratio method was used to follow the probe spectral changes as a function of the degree of polymerization. Linear correlation plots between the intensity ratios as measured from the probe fluorescences and the degree of cure were obtained for varieties of photocurable resins with UV or visible initiators. In addition, a fluorescence probe technique for measuring coating thickness based on the nascent fluorescence from coating substrate is also described.