Strictly alternating polyamides with stiff and flexible chain segments: Effects on thermotropic liquid crystallinity of the introduction of an ethylene unit into the mesogenic group

Bipolyamides containing mesogenic groups were prepared by solution polycondensation from aromatic dicarbonyl dichlorides and novel diamines. Ortho‐substitution and the aliphatic chain length of α,ω‐bis(4‐aminophenyl)alkylenes affected the thermal transitions of the resulting polyamides profoundly. Introduction of an ethylene unit into the stiff biphenylene segment not only reduced the isotropization temperatures, but also depressed the tendency to form liquid crystals.