ORIENTATIONAL ELASTIC-CONSTANTS OF POLYMER COMB-LIKE NEMATIC

Elastic deformations of uniformly orientated layers of thermotropic po lymeric comblike nematic in magnetic field were studied using the meth od of Freedericksz transitions. The temperature dependences of splay K -1 and bend K-3 elastic constants and optical anisotropy were determin ed. On clanging of the relative temperature Delta T = T - T-o from -0. 5 to -60 degrees C, the optical anisotropy increases from 0.05 to 0.1. This experimental fact shows double increase of order parameter. It w as found that in investigated temperature range the splay constant val ues are slightly more then the bend constant values (K-1/K-3 similar t o 0.8).