Some physicochemical studies on binary organic eutectic and monotectic alloys: p-dibromobenzene- m-aminophenol system

Abstract

The phase diagram of p-dibromobenzene- m-aminophenol system, determined by the thaw–melt method, shows the formation of a eutectic at 86.8 °C and a monotectic at 120.0 °C at 0.9899 and 0.0496 mole fractions of p-dibromobenzene, respectively. Growth data for the pure components, the eutectic and the monotectic, determined by measuring the rate of movement of solid–liquid interface in a capillary at different undercoolings (Δ T) suggest the applicability of Hillig–Turnbull equation, v= u (Δ T) n , where u and n are constants depending on the nature of materials involved. The values of enthalpy of fusion of the pure components, the eutectic and the monotectic were determined and from these values, the enthalpy of mixing, entropy of fusion, Jackson's roughness parameter and excess thermodynamic functions were calculated. Optical microphotographs of the pure and binary materials show their characteristic features.