OPTICAL ANISOTROPY OF COMB-LIKE MACROMOLECULES OF LATERAL AND SEMILATERAL STRUCTURE

Maxwell effect and Kerr effect techniques were used to study the intra molecular axial ordering of anisotropic side groups of an isolated mac romolecule in solution. Three comb-like polymers with a methacrylic ma in chain were investigated. The side chains contain aliphatic spacers separating the mesogenic fragments R from the backbone. R contains two or three phenylene rings with ester linking groups and cyano end grou ps. Fragments R are attached to the side chains, by the end or middle- point, through the para- or ortho-phenylene ring. The main-chain confo rmation in solution was identified to assess the hydrodynamic data usi ng the Gaussian coil approximation. The optical anisotropy of the macr omolecule segment was determined and related to the monomer unit struc ture. The specific Kerr constant obtained in diluted benzene solution of polymer was compared with those of low molecular weight analogues o f the polymer mesogenic groups. The mobility and intramolecular orderi ng of the mesogenic groups in the isolated macromolecules are discusse d. These properties are compared with those of comb-like polymers with another type of attachment of mesogenic groups, and with another (sil oxane) chemical structure of the backbone chain. The differences in re strictions of side-chain mobility due to the backbone linkage in diffe rent types of comb-like polymers are also discussed.