Abstract
The birefringence of some polymeric esters of alkoxy benzoic acid (PEABA) in tetra chloromethane (TCM) was determined by previously proposed interferometric methods in polarized light. An increase in PEABA birefringence when an external electric field acts on the liquid crystal layer was evidenced in this paper. The decrease of PEABA birefringence with the increase in the alternate electric field frequency was also evidenced. The dipolar nature of the collective interactions between the side-chains of PEABA in liquid crystalline phase and also the viscosity of the lyotropic liquid crystal obtained by mixing PEABA with TCM in concentrations of about 10-2 g / cm3, at room temperature are sustained by the results obtained in this paper. Keywords: PEABA birefringence, tetra chloromethane (TCM), polarized light