Factors Affecting the Tensile Properties of Nonmercerized and Mercerized Cotton Fibers

When a G. hirsutum cotton fiber was suspended under tension in water and then allowed to dry without removing the stress, its strength increased and its extensibility decreased. If the sample was slack mercerized before the treatment, its strength and extensibility changes were not as marked. The altered properties of the nonmercerized cotton are ascribed to the water inducing plasticization of the fiber, thus permitting the structural units of the sample to readjust as its convolutions began to untwist and as creep occurs. By comparing the properties of the nonmercerized and mercerized counterparts, we propose that the increased strength and extensibility of cotton with slack mercerization is due to the swelling effects of this treatment, which causes un twisting of the fiber and reduces its degree of crystallinity and its crystallite lengths.