ELASTIC DEFORMATIONS IN MAGNETIC-FIELD OF A LIQUID-CRYSTALLINE POLYMER HAVING MESOGEN GROUPS IN THE BACKBONE AND GRAFTED CHAINS

The elastic orientational deformations in magnetic field and the tempe ratures of phase transitions were studied for a hybrid thermotropic li quid-crystalline aromatic polyester, having mesogen groups in both bac kbone and grafted chains in the range of molecular masses from 900 to 10200. It was found that in the studied range of molecular masses bire fringence of totally oriented nematic and, hence, its orientational or dering are independent of molecular mass. On changing the relative tem perature from -2 to -30-degrees-C, the order parameter of orientation increases from 0.35 to 0.55. The bend elastic constants are on the sam e order with those of previously investigated nematics (both high- and low-molecular-mass). No dependence of the constants upon molecular ma ss was found.