New Phases in the Ferroelectric Liquid Crystal MHPOBC Studied by Differential Scanning Calorimetry

Phase transitions of L - and D -enantiomers of 4-(1-methylheptyloxycalbonyl)phenyl 4'-octyloxybiphenyl-4-carboxylate (MHPOBC) were studied by the DSC method. Two new phases have been observed between the smectic A phase and the smectic C * phase and between the smectic C * phase and the third stable state ( S Y * phase) in both L - and D -MHPOBC. The new phases disappear by the introduction of more than 3% D -MHPODC into L -MHPOBC and vice versa . A phase diagram was constructed for the enantiometric mixture of L - and D -MHPOBC.