抄録
The dielectric dispersions in copolymers of the methyl acrylate with styrene and of the ethyl methacrylate with styrene were measured at the temperatures from -75°C-140°C in the frequency range of 30c/s∼100kc/s. In the copolymers of methyl acrylate with styrene, two distinct tanδ maxima based on α-and β-relaxation processes were observed. The tanδ maximum corresponding to α-relaxation shifted to higher temperatures with decrease of methyl acrylate content, while the one corresponding to β-relaxation shifted to lower temperatures with decreasing methyl acrylate content. The latter effect is attributed to the dipole-dipole interactions of ester side chains. On the other hand, in the ethyl methacrylate-styrene copolymers, the change in composition did not affect the position of tanδ maximum corresponding to β-relaxation. The values of apparent activation energy of dielectric relaxation were obtained for methyl acrylate-styrene copolymers.
