Abstract
The effects of heat-treatments of acrylic fibre on its fine structure have been investigated to discuss the relation between dyeing properties and fibre structure.
Samples of Orlon 42 were treated with hot water (100-150°C), steam (100-150°C), and hot air (100-200°C) without tension, and then their fine structures (orientation, crystal size and crystallinity) were checked by means of X-ray diffraction.
X-ray scattering intensities were measured with a Shimadzu diffractometer using Geiger counter and Cu Ka radiation.
The dynamic loss tangent was measured over a range of temperature from 20° to 170°C with a Toyo-Sokki dynamic viscoelastometer using 138 cps. And the temperature-range properties of Astrazon Blue FGL on the fibres were examined.
The results of measurements were as follows: The degree of orientation is decreased, the crystal size increased, and the crystallinity slightly increased by both the wet heat-treatment and dry heat-treatment.
Two loss tangent maxima occures at about 120°C and 135°C. The loss peak at 120°C may be due to the motion of segments in the amorphous region, and the other loss peak at 135°C may be due to the motion of segments in the intermediate region between crystalline and completely amorphous regions.
The heights of the loss peaks increases on wet heat-treatment, but decreases slightly on dry heat-treatment.
This may be explained by the conversion of some part of intermediate regions into amorphous. region on wet heat-treatment, and vice versa on dry heat-treatment.
