ABSTRACT

In the past, most of the effort in obtaining highly oriented polymer samples has been concentrated on trying to uncoil and align long polymer molecules in the solid state, melt, or solution. A wide variety of techniques have been employed with conventional polymers such as polyethylene. These have included ultra-drawing [1–3], high degrees of extrusion [3–5], and gel or solution spinning [6,7]. Also, new, rigid rod polymers have been developed from which highly oriented fibers can be prepared by the spinning of liquid crystalline solutions [8–10]. Significant improvements and developments have taken place over recent years, and samples with high values of modulus and strength have been prepared. However, perfect molecular alignment as in single crystals is never achieved using such approaches, since defects such as chain ends, chain folds, loops, and entanglements are invariably trapped in the structures.