Abstract
Terephtal-bis-p-n-decylaniline (TBDA) exhibit a weakly first order Sm A‒Sm C Phase Transition Whereas TBBA, a lower homologue of the same series, exhibit a second order Sm A‒Sm C transition. In order to investigate the tricritical point (TCP) of Sm A‒Sm C transition, a systematic study of binary mixtures of TBBA + TBDA are undertaken. DSC and polarizing thermal microscopy studies infer the TCP of the Sm A‒Sm C Transition at the weight percent of 80.05 TBDA in TBBA. We report here a systematic study of the approach of TCP by DSC and density measurements as a function of temperature in few compositions of TBBA + TBDA on both sides of the tricritical point.