PRIMARY AND SECONDARY RELAXATIONS IN ALIPHATIC-ALCOHOLS - COMPLEX DIELECTRIC PERMITTIVITY SPECTRA OF 5-METHYL 2-HEXANOL

The real and imaginary parts of the complex dielectric permittivity of 5-methyl 2-hexanol have been measured in the frequency range 10 Hz to 100 kHz and temperature range 77 K to 200 K. The results show the exi stence of two Arrhenius relaxation processes, assigned as alpha and be ta. It is found that these processes co-exist above the glass transiti on temperature, T-g. However the beta process persists in the glass st ructure with continually reduced dielectric relaxation strength and br oader distribution of dielectric relaxation times with a reduction in temperature. This continues on until some 60 K below T-g. Our investig ation of these processes in this material and other materials already published support the glass transition theory of Johari and Goldstein that beta process is generic to the glass phase of supercooled liquids . A plausible explanation of the Arrhenius nature of the cl relaxation process for alcohols is also given.