The dielectric relaxation of binary mixtures of propanediamine and propanediol

Dielectric spectra of binary mixtures of propanediamine (PDA) and propanediol (PDO) are measured by TDR (time domain reflectometry). The KWW (Kohlrausch-Williams-Watts) function is used to obtain relaxation parameters. The observed relaxation time has a maximum at around 0.7 mole fraction of PDO. The concentration dependence of the relaxation time suggests that the intermolecular interaction between PDA and PDO is stronger than that of pure amines and of pure alcohols.