Thermotropic Liquid Crystal Polymers with Flexible Chain Elements. Synthesis, Spinning and Mechanical Properties
Abstract
A thermotropic LC aliphatic polyether inspired by cellulose, featuring flexible comonomer isomorphous with the rigid monomer was prepared and spun, as well as an LC polyester incorporating heteromorphous flexible comonomer. Upon spinning, both materials exhibit high molecular orientation; the polyether with isomorphous flexible units shows extremely rapid crystallization, whereas the polyester forms an oriented glass — a solidified nematic melt.
Both types of yarns showed disappointing mechanical properties. We rationalize these observations by chain folding, resulting in a pseudo-lamellar structure of the liquid crystalline melt which cannot form in all-aromatic polyamide solutions or all-aromatic polyester melts. In the case of the more ordered polyether system, experimental evidence for lamellar organization was secured.
Keywords
Ethylene Oxide Azelaic Acid Cationic Polymerization SAXS Pattern Yarn PropertyPreview
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