Polychloroprene degradation by a photo-Fenton process: The effect of solvent

The degradation of polychloroprene (PCP) by photo-Fenton process using FeCl3·6H2O and solvents with different properties was studied by measuring the efflux time in an Ubbelohde capillary viscometer. The solvents benzene, toluene, chloroform, and THF (tetrahydrofuran) were investigated with regard to their influence on the curves of efflux time as a function of reaction time for the system exposed to light at a constant temperature. PCP degrades in these conditions, and the phenomenon is strongly dependent on solvent type. The degradation kinetics was also investigated based on efflux time data. At short reaction times (0-215 min), the curves of efflux time vs. reaction time fitted a second-order kinetic model for the different studied solvents. On the other hand, when the time interval was increased to 515 min, the adjustment was achieved only for curves obtained using THF and chloroform. The solvent properties, such as dielectric constant, dipole and surface tension can be correlated with the efflux time data collected for the PCP degradation. The reaction proceeded faster in benzene when compared with the three other studied solvents.