LIQUID-CRYSTALLINE ORDERING IN MELTS OF THERMOTROPIC POLYMERS WITH MALONIC-ACID FRAGMENT IN SPACER

With object to evaluate the effect of spacer chemical composition on c hain conformation of thermotropic polymers in liquid crystalline (LC) state, linear and combined (main chain/side chain) polymers, containin g fragment of malonic acid (FMA) in methylene spacer were studied. It is shown that owing to presence of FMA chain conformations of the stud ied polymers differ substantially from those of RF-polymers with simpl e methylene spacer. In lc melt the main chain of polymers investigated has ''hairpin''-like conformation with parallel allignment of neighbo uring mesogens. In the case of combined polymers the side chain is loc ated inside the hairpin, and mesogens of both main and side chains are found to be mutually parallel. Described polymer structure in LC melt provides the explanation for experimentally observed similarities bet ween properties of LC melts of studied polymers and those of low molec ular weight liquid crystalls.