Effect of Aging on Properties of Webs and Micro-Structure of Acrylic Fiber

Wet-spun acrylic fiber was aged for 2.5 months at various temperature (5-35°C) and humidity (65, 90%RH), and changes of elastic properties of the fiber webs and their fiber micro-structure were investigated, and the mechanism of their changes was studied. Acrylic fiber aged at the higher temperature and humidity (i. e., at 35°C, 90%RH) showed 1) the larger elastic recovery and the smaller creep elongation and 2) the higher capacity of water absorption. For the fiber aged under these condition, content of the combined water, which was chemically combined with CN group in acrylic polymer and oriented parallel to fiber axis, was higher than that for the fiber aged at lower temperature and humidity. Increase of the combined water, by aging at higher temperature and humidity just as at weather condition of summer in Japan, is presumed to cause improvement of the elastic recovery of acrylic fiber.