N,N-DIMETHYLFORMAMIDE PLUS 1,2-DIMETHOXYETHANE BINARY-MIXTURES - THE STATIC DIELECTRIC-CONSTANT FROM 40 TO 80-DEGREES-C

The static dielectric constant (epsilon) has been measured at 2 MHz fo r N,N-dimethylformamide (1), 1,2-dimethoxyethane (2), and their nine b inary mixtures covering the whole miscibility field (0 less-than-or-eq ual-to x1 less-than-or-equal-to 1) in the 40-80-degrees-C temperature range. The experimental epsilon values were fitted by empirical equati ons of the types epsilon = epsilon(T), epsilon = epsilon(x1), and epsi lon = epsilon(T,x1). The mixing quantity deltaepsilon has been evaluat ed and fitted by a Redlich-Kister equation. The trend of deltaepsilon vs mole fraction curves shows negative deviations from ideality, and m akes evident the presence of a stable dipolar interaction between unli ke molecules.