STRUCTURE OF A SELF-ASSEMBLED HYDROGEN-BONDED LIVING MAIN-CHAIN LIQUID-CRYSTALLINE POLYMER

A main chain hydrogen-bonded liquid crystalline polymer was formed by melt mixing two complementary components, A and B, which in their indi vidual states do not exhibit liquid crystallinity. The structure of th e polymer and the thermal stability of its mesophase were studied usin g synchrotron radiation SAXS/WAXS/DSC at Daresbury (UK) and by variabl e temperature Fourier transform infrared. The chain extension, or ''po lymerization'' process, was accelerated at the point when the polymer formed a liquid crystalline phase upon cooling from the isotropic melt . The polymer has an aabb chain structure and forms a smectic layer wi th a length of the A-B repeating unit. The hydrogen-bonded main chain polymer studied here is a monotropic liquid crystal. Above 150 degrees C, it exhibits kinetic stabilization of its monotropic smectic phase. (C) 1998 John Wiley & Sons, Inc.