SPECIFIC CONFORMATIONAL FEATURES OF THERM OTROPIC POLYMERS CONTAININGA MALONIC-ACID FRAGMENT IN THE FLEXIBLE SPACER

To disclose the effect of the structure of spacer on chain conformatio n of thermotropic LC polymers, we studied linear and mixed (with mesog enic groups both in the main and the side chains) thermotropic polymer s, containing the malonic acid fragment in methylene spacer of the mai n chain. It was found that incorporation of the malonic acid fragment results in a chain conformation that is dramatically different from th at characteristic of conventional RF polymers with methylene spacers. In the LC melt, the main chain of the polymers acquires a ''hairpin'' conformation described by parallel alignment of neighboring mesogenic fragments. In the mixed polymer, the side chain is located inside the hairpin, so that the mesogens of the main and the side chains are arra nged in parallel.