Effect of hot drawing on the structure and properties of novel polyamide 5,6 fibers

Abstract

Polyamide 5,6 (PA 5,6) fibers were prepared using the melt-spinning method. The effects of draw ratio and temperature on the structure and properties of PA 5,6 fibers were investigated by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction, sonic velocity and tensile test measurements. DSC results revealed that the melting temperature showed no considerable variation, while the heat of fusion increased with increments with draw ratio and temperature. It was found that the crystallinity and crystal size of PA 5,6 fibers were directly proportional to the draw ratio and temperature and the orientation factor increases as expected upon drawing. The tenacity and Young's modulus were found to be increased, while the elongation at break decreased with the draw ratio and temperature. The improvement in mechanical properties may be attributed to the increase of orientation along the fiber axis and the crystallinity.