The precursors of the present thermotropic hydrogen bonded binary mixtures investigated are prepared from Palmitic acid (PA) and p,n-alkyloxy benzoic acids. PA + 8BAO complex is chosen as one of the chemical ingredients referred as X and PA + 11BAO & PA + 12BAO are referred as Y ingredients to obtain binary mixtures as the individual complexes possesses rich phase polymorphism. As a result, two sets of binary mixtures are formed that is PA + 8BAO: PA + 11BAO and PA + 8BAO: PA + 12BAO which yielded nine binary mixtures of former and later in molar proportion from 0.1 to 0.9. Optical and thermal properties of eighteen binary mixtures are extensively studied.