Synthesis and Diffusion Behavior of Thermotropic Poly(ether-amides)

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A new class of thermotropic, main-chain poly(ether-amide)s will be prepared in both deuterated and nondeuterated forms as model polymers for the investigation of diffusion behavior in liquid- crystalline (LC) polymer melts. The target polymers will be prepared by melt polymerization and peptide synthesis methods with sufficiently high molecular weights to form entangled melts in the isotropic state. The mesophase properties of these polymers will be evaluated. Forward recoil spectrometry (FRES) will be used to determine the concentration profiles of these interdiffusing LC polymer chains. Both tracer and self-diffusion studies of LC polymer chains in their smectic, nematic, and isotropic phases will be undertaken. The effect of the degree of chain orientation induced by poling in either magnetic or electric fields will also be explored for its effect on the LC polymer diffusion characteristics. Collaborations are planned which will further characterize these thermotropic polymers using rheological measurements. This research is part of an ongoing effort in several laboratories to understand the behavior of LC polymer, which have increasing use as structural materials.