New fluorescent probes for monitoring the polymerization reaction: p-vinyliden derivatives of N,N-dimethylaminoaryl compounds

The fluorescence emission of two new fluorescent probes have been studied in environments of different polarity and viscosity. The probes have been shown to be sensitive to changes in both microviscosity and micropolarity of the surroundings, and their dipolar moments in the excited state have been estimated. They have been used as fluorescent sensors to monitor the photopolymerization reactions of some mono- and di-functional (meth)acrylate monomers, and two commercial photocurable acrylic adhesives. The fluorescence emission band of the probes showed an increase in intensity as the degree of conversion increases, throughout the entire polymerization range in the different systems checked. Their sensitivity have been compared with that of their parent compound N,N-dimethylamino-bencilidenenmalononitrile.