Cure Characterization of an Epoxy Network by Fluorescence Behaviour of trans-Diaminostilbene

摘要

One of challenging problems in polymer science remains the characterization of crosslinking in thermoset polymers. The development of new methods to probe cure reactions has been one of the major research efforts in our laboratory in recent years. We took an approach based on labelling with reactive dyes to mimic the reactivities of the curing agent. The photochemical and photophysical behavior of the reactive label provides information on the curing process. The fluorescence intensity of the DAA label at 560 nm increases sharply (more than 100 times), because the fluorescence quantum yield of DAA increases more than a thousand-fold when the amine groups of DAA become tertiary amines. Since the effect of the viscosity change as cure proceeds was negligible when monitored at 20 C, the fluorescence intensity has been used to follow cure reactions in a quantitative way, especially in the later stages of cure (after gelation). Epoxy materials, Reprints. (JES)