The electric conductivity and morphology of a series of polyethylene blends
with elastomers filled with carbon black were studied. For all the heterog
eneous blends investigated the phenomenon of superadditive electric conduct
ivity was observed under certain conditions. If the concentration of carbon
black in each phase is lower than;the critical value, this phenomenon is c
aused by a partial transfer of carbon black to the polymer interfaces. When
the carbon black concentration in one of the blend phases is above the cri
tical value, the observed phenomenon is explained to a marked extent by the
localization of carbon black in one of the polymer blend phases, while the
absence of the above-mentioned transfer is completely related to this proc
ess.