Phase transition temperatures, densities, rotational viscosities and their activation energies are determined for 4-cyano derivatives of biphenyl (4-cyano-4'-pentylbiphenyl and 4-cyano-4'-heptylbiphenyl) and phenylcyclohexane (trans-4-heptyl-(4'-cyanophenyl)-cyclohexane and trans-4-pentyl-(4'-cyanophenyl)- cyclohexane) mixed with azoxy compounds (4-butyl-4'-methoxyazoxybenzene and 4-butyl-4'-heptanoyloxy-azoxybenzene). Macroscopic properties of the mixtures comprising 4-cyano-4'-alkyl-biphenyls (CB) as the polar compounds are found to differ significantly from those comprising trans-4-alkyl-(4'-cyanophenyl) cyclohexanes (PCH). The results obtained are discussed in terms of specific intermolecular interactions and associate formation.