SYNTHESIS AND CHARACTERIZATION OF LIQUID-CRYSTAL POLYCARBOSILANES - POLY(1-METHYL-1-SILAETHYLENE), POLY(1-METHYL-1-SILABUTANE) AND POLY(1-SILABUTANE) WITH PENDANT MESOGENIC GROUPS

The synthetic routes for preparation of side chain liquid crystal poly carbosilanes, with rod type mesogens, pending from every second and ev ery fourth atom in the main chain, forming 'comb-like' and 'double com b-like' polymers, are described. Structure-property relationships were investigated. X-ray measurements of the smectic materials, oriented i n a magnetic field, proved the S-Al phase to be a dominant one for the se new mesomorphic polymers; however, generation of S-Ad and more orde red S-B phases was also detected. Polycarbosilanes present useful, hig hly thermally and chemically resistant materials, which provide useful models for studies of the influence of the main chain architecture on the properties of polymers with various pendant groups. Copyright (C) 1996 Elsevier Science Ltd.