Shrinkage and mechanical structural variations in cold drawn perlon fibers

Abstract

In the present work nylon 6 (perlon) fibers were stretched at room temperature. The Pluta polarizing interference microscope with a micro-strain device was used for measuring some optical and mechanical parameters of the fibers. The values of the fully oriented refractive indices n 1 and n 2 were found to be 1.630 and 1.561. The generalized Lorentz–Lorenz equation given by de Vries was used to determine structural parameters of the fibers. Comparison between Herman's optical orientation function formula and the corrected formula by de Vries are given. The changes in the molecular orientation were evaluated to obtain the values of orientation functions f 2( θ), f 4( θ), f 6( θ), < P 2 (cos θ)> and < P 4 (cos θ)>. In addition, the shrinkage stress was found to increase with increase of the draw ratio. The dielectric constant, the dielectric susceptibility and the number of moles of network chains per unit volume were also calculated. Microinterferograms and curves are given for illustration.