Determining Polyester Fiber and Microfiber Structure by Iodine Sorption

Abstract

The characterization of polyester fiber structure is classically founded on several physicochemical techniques. One of the most common is iodine sorption, and we have modified this technique by increasing its capacity of analyze. With our modification, it is possible to distinguish various fibers without ambiguity. We use this new technique to characterize three polyester fibers: a microfiber, a 14 μm circular fiber, and a trilobal fiber. Virgin fibers of each type are divided into batches; each batch is subjected to heat setting in a vapor medium at a specific temperature and then tested. This procedure allows follow-up of the transformation of the fiber structure. Such an evolution provides information on the interactions of macromolecular chains. The different tests show that the polymer of the microfiber has a very particular organization, which mixes great accessibility with a significant rate of crystallinity. The sorption curves of iodine indicate that the trilobal fibers have an overall structure that is less differentiated than the other fibers.