HYDRODYNAMIC PROPERTIES AND EQUILIBRIUM R IGIDITY OF A COMBINED MESOGENIC POLYMER CONTAINING BIMETHYLENE FRAGMENTS IN THE MAIN-CHAIN

Hydrodynamic and conformational characteristics of a combined mesogeni c polymer containing bimethylene and hexamethylene spacers in the main chain and the side chains, respectively, were studied in dilute solut ions by means of sedimentation-diffusion analysis and viscometry. The length of the Kuhn segment A = 23 x 10(-8) cm and hydrodynamic radius d = 13 x 10(-8) cm obtained for the polymer chain give a large ratio d /A = 0.57, which is typical for the comb-shaped molecules of combined polymers. The number of monomer units in the Kuhn segment of the exami ned polymer (S = 1.1) is by 1.8 times greater than S = 0.6 reported fo r a combined polymer containing hexamethylene spacers in the main chai n. Quantitative analysis reveals that these differences are associated with an increase in rigidity of the main chain because of the shorter methylene spacer, rather with steric interactions between the side gr oups.