Interconversion of mechanical and dielectrical relaxation measurements for dicyclohexylmethyl-2-methyl succinate.
A comparison between results of dielectrical relaxation and dynamic mechanical spectroscopies is carried out for the alpha-relaxation of the ester dicyclohexyl methyl-2-methyl succinate (DCMMS). The results for the dielectric permittivity and the shear modulus measurements are presented according to the empirical Havriliak-Negami (HN) equation. By using the time-temperature principle a master curve in each case was obtained for several temperatures. The comparative analysis presented here is based on the assumption of a relationship between rotational and shear viscosities. The former one is associated to the dielectrical relaxation, whereas the latter is associated to mechanical relaxation. Both viscosities are not necessarily equal in general, and we assume that the difference between them is an important factor to appropriately compare the dielectrical and mechanical results.
Díaz-Calleja
R
R
Departamento de Termodinámica Aplicada, Universidad Politécnica de Valencia, Valencia E-46071, Spain. rdiazc@ter.upv.es
Garcia-Bernabé
A
A
Sanchis
M J
MJ
del Castillo
L F
LF