Dyeing of Polyacrylonitrile Fibers

Abstract

A new method for the study of dyeing rates and equilibria combines the accuracy and ease of various other methods used previously. The dyehaths are closed systems in Erlenmeyer flasks modified to provide very efficient agitation during horizontal motion of a holding tray in a shaking bath of good temperature constancy. When a stopcock is opened, pressure inside the flasks pumps the solution directly into modified spectro photometer cells. Dilution is avoided by the use of spacers and various parts of the dye spectrum, so that the measured solution can be returned to the system. Illustrative ex amples include the effect of steam annealing temperature, orienting stretch sequence, and shaking speed on the dyeing rate of polyacrylonitrile fibers with Malachite Green, dyeing rate with Orange II on various fibers, its concentration dependence on poly acrylonitrile fibers and desorption with temperature increase. Many of the methods can be used for other than dyeing studies.