10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 4 2012(October - December) The density (ρ), refractive index (n lessThan sub greaterThan D lessThan /sub greaterThan ) lessThan sub greaterThan , lessThan /sub greaterThan dielectric constant (e lessThan sub greaterThan s lessThan /sub greaterThan ) and relaxation time (t) of binary mixture of Allyl Bromide (AB) with polar protic solvent 2-Butanol including those of the pure liquids, were measured over the complete composition range. The experimental data is used to calculate excess molar volumes (), excess dielectric constant (e lessThan sub greaterThan s lessThan /sub greaterThan lessThan sup greaterThan E lessThan /sup greaterThan ), excess inverse relaxation time (1/t) lessThan sup greaterThan E lessThan /sup greaterThan , excess molar refraction (R lessThan sub greaterThan m lessThan /sub greaterThan ) lessThan sup greaterThan E lessThan /sup greaterThan , Bruggeman factor (f lessThan sub greaterThan B lessThan /sub greaterThan ). The variation of these parameters with composition and the effect of bonding in new chemical species were discussed from the point of view of intermolecular interactions in these mixtures. The decrease in excess molar volume () is attributed to the formation of hydrogen bonded associated species formed between unlike molecules. ARUNA P. MAHAROLKAR , A. MURUGKAR, S. S. PATIL AND P. W. KHIRADE. dielectric constant, relaxation time, intermolecular interactions 438-444