CONSEQUENCES OF THE JACKETED EFFECT ON MESOMORPHIC AND ORIENTATIONAL PROPERTIES OF SIDE-ON FIXED LIQUID-CRYSTALLINE POLYMERS

The mesomorphic properties have been studied as a function of the degree of polymerization for certain 'side-on fixed' polyacrylates. A peculiar evolution of the clearing temperature, T(IN), as well as of the glass transition temperatures, T(g), revealed that beyond a certain backbone length, T(IN) and T(g) decrease as the main chain length increases. The nematic 'jacketed' structure of these polymers induces a more or less high anisotropy of the polymer backbone conformation in the nematic phase and this can counterbalance the usual effect of an increase in the degree of polymerization on the thermodynamical properties of these systems. This evolution allows us to explain the unusual diamagnetic anisotropy anomaly observed as a function of temperature for this type of polymer.