DIELECTRIC PROPERTIES OF LIQUID ETHANOL AND 2-PROPANOL (PART 1). DIELECTRIC PROPERTIES OF TRIMETHYLENE GLYCOL (PART 2)
Abstract:
Dielectric constant and loss measurements of liquid EtOH and 2-PrOH were obtained from room temperature to -160 deg C for the pure liquids and mixtures with small amounts of H2O to facilitate supercooling. Two distinct dispersion regions were found below -100 deg C in the range from 1 c to 5 mc. The temperature dependances were similar and described by rate laws of the form found for similar measurements in 1-PrOH. The magnitudes and temperatures dependances of the equilibrium dielectric constants are discussed in terms of Kirkwoods theory. An explanation of the multiple dispersions is discussed in terms of H bond breaking to permit reorientation fo alkyl and hydroxyl groups. The dielectric constants and loss of trimethylene glycol were measured in the range 1 to -70 deg C at frequencies below 5 mc. The results indicate that the complex dielectric constant is not represented by a Debye function, but can be fitted by an empirical dispersion function of the same form describing measurements for glycerol and propylene glycol. The measured properties are intermediate between those for the latter 2.