Thermal aftereffect

The third therm represents the field characterising the thermal aftereffect. This is given by... 

The temperature coefficient of irreversible polarization losses are smaller, the stronger the coercive field. Partial substitution of Nd by Dy increases coercivity and the irreversible polarization losses decreases. The polarization losses due to thermal aftereffect decrease with temperature (Rodewald 1985a, b). 

Reaction lOe is relatively slow in the Re2(CO)io initiating system, and the thermal reaction between Re(CO)6 formed in 10a and CCI4 generated CCI3 radicals thermally in the dark and so is responsible for the aftereffect. However, Mn2(CO)io reacts rapidly according to lOe and no aftereffect is observed for the Mn2(CO)io/CCl4 photoinitiating system,... 

After irradiation, the polymer becomes less thermally stable (Figs. 90 and 91). This aftereffect phenomenon can be explained by the formation of free radicals capable of initiating thermal and thermooxidative decomposition during the process of irradiation. Table 12 presents the values of the rate of dehydrochlorination of polyvinyl chloride in the case... 

TABLE 14. Influence of Aromatic Hydroxyketones, Phenols, and Certain Analogs of These Compounds on the Rate of Thermal Dehydrochlorination of PVC and Aftereffect in Ultraviolet Irradiation of the Compositions... 

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