Some unusual structures in thermotropic mesophase polymers

Random copolymers of polyester type have been shown to exhibit simultaneous crystallization into two different crystalline forms which are transformed into different hexagonal mesophase structures on heating. Some of these po lymers have been found to form LC aperiodic smectic structures. Liquid Crys tal elastomers, H-bonded networks and grafted LC materials are discussed. M echanical field creates the director reorientation in monodomain elastomers and H-bond networks which is discussed in terms of "soft elasticity". Graf ting of particular LC polymer on fluorine containing polymer support result s in the formation of composite sandwich-type material. Mechanical deformat ion leads to the macroscopic alignment of the LC grafted layer. There is a pronounced memory effect, which is manifested in the macroscopic alignment of the grafted layer under cooling from an isotropic to a LC state. The phe nomenon observed results from the strong influence of the polymer support o n the LC director orientation. The optical and mechanical properties of san dwiched samples can be regulated in wide limits.