| Abstract: | Dielectric relaxation studies of poly(propylene glycol), average molecular weight 2000 g mol?1, in dilute solution of cyclohexane, decaline, benzene and carbon tetrachloride have been carried out at 10.10 GHz and 35 °C. Average relaxation time τ0, and relaxation times corresponding to segmental motion τ1, group rotations τ2 and dipole moment µ have been determined. It is found that τ0, τ1 and µ are influenced by the solvent environment while the τ2 value is solvent‐independent. A comparison has been made with the dielectric behaviour of poly(ethylene glycol), average molecular weight 1500 g mol?1, in dilute solutions of benzene and carbon tetrachloride because both systems have an equal number of monomer units. The effect of methyl side‐groups on dielectric relaxation in poly(propylene glycol) molecules is discussed. The Kirkwood correlation factor is also evaluated in dilute solutions with concentration variation and it is found that these molecules exist in cluster form due to intermolecular hydrogen bonding. © 2000 Society of Chemical Industry |
