A Rheological Investigation of a Semi-Stiff Chain Aromatic Polyamidehydrazide in Dilute Solution: Ultra-High Modulus Fibers and Liquid Crystalline Polymer Solutions

Abstract

The production of ultra-high modulus polymeric fibers (1), having a tensile strength comparable to that of steel wire, is based on the ability to achieve a very high degree of long range molecular order (2) during the spinning process. The realization of such high degrees of orientation can be facilitated by solution spinning polymers which are capable of forming a lyotropic, nematic mesophase, i.e. a liquid crystalline solution. The spinning and stretching processes orient the liquid crystal such that the chains are uniaxially oriented with respect to the fiber axis. The solvent is then rapidly removed so as to freeze in the high degree of orientation.