Abstract: The dielectric relaxation measurements for some AB crosslinked polymers based on cas-tor oil were carried out as a function of temperature from -180℃ to 140℃ at different fre-quencies. The multiple relaxation and phase behaviors of AB crosslinked polymers wereinvestigated with the dielectric spectroscopic analysis.The two components showed compati-bility or near compatibility based on the dielectric relaxation spectra.The secondary relaxation was attributed to the local motion of the chain segments ofpolyurethane component. The interfacial polarization of the AB crosslinked polymers wasdescribed according to a method deduced in our laboratory.The activation energies of inter-facial polarizaticn,which are related to the size of domains and the interfacial interactionbetween different components as well as the flexibility of the molecular chain in these samples, were calculated.

Key words: AB crosslinked polymers, Polyurethane based on castor oil, Dielectric property