Ultrafine synthetic fibers have much usability such as artificial leather and high quality fabric. But these have also shortcomings in dyeing for it is difficult to dye in deep color. Recently, poly(vinyl alcohol) (PVA) microfibrillar fiber has prepared by improved saponification method proposed by Lyoo. PVA microfibrillar fiber has some similarities with natural fibers in microfibrillar structure and abundant microcavities due to self-assembly molecular ordering. Especially, ultrafine PVA microfibrillar fibers were expected to be dyed in deep color because of their abundant reactive side groups and microcavities for fixation of dye figments as well as enlarged surface area. Microfibrillar fibers were formed by the assembly of multiple microfibrils. Therefore it is difficult enough to standardize the basic physical properties, such as diameter, fiber length distribution, surface area per unit mass, and so on. Surface area of PVA microfibrillar fiber was suspected to have enormous effects on dyeing properties and establishment of its evaluation methods were essential. In this study, PVA microfibrillar fibers were treated with reactive dyes. PVA microfibrillar fibers showed relatively high dye absorption than reported other synthetic fibers. To investigate the effects of surface area enlargement, PVA monofilaments, which were prepared by spinning, were also treated with reactive dyes. Dye exhaustion was evaluated by the change of amount of light absorbance in wavelength of maximum absorption. Comparison of dye uptake needs some assumption; PVA microfibrillar fiber and monofilament has the same surface characteristic and crystallinity (or amount of amorphous region). PVA microfibrillar fibers were controlled by saponification and following drawing conditions to match the degree of crystallization with that of PVA monofilament. From these results, we can roughly estimate the surface area of PVA microfibrillar fiber.
By: Won Seok Lyooa, Han Do Ghimb, Sam Soo Kima, and Jae Pil Kimb aSchool of Textiles, Yeungnam Universi
Submit Date: 6/7/2010 18:00