Fluorescent molecular rotors as probes for polymers

The use of a molecular rotor (1,1-dicyano-4-(4'-dimethylaminophenyl)-1,3-butadiene) as a fluorescent probe was proved to be of great interest for the study of polymers. First, the rotor can detect the critical time of the glass effect in the bulk polymerization of MMA into PMMA due to viscosity change, this will allow a better control of the process and is complementary to the information issued from the use of the fluorescent pyrene probe which is sensitive to the gel effect. Second, the cinnamylidene rotor was able to detect the formation of hydrophobic microdomains for cationic amphiphilic polymers in their aggregation modes when they were solubilized in water, both polarity and viscosity changes are playing a role. The possibility of incorporation of various molecular fluorescent rotors in polymers beads was also studied.