The impact of processing conditions on the structural and optical properties of the as‐spun polyamides fibers

Abstract

The development of crystallinity and orientation during the melt spinning of polyamides (nylon 66) was investigated. This study reports the question of the orientation and crystallinity determination of nylon 66 by means of differential scanning calorimetry, optical polarized microscope, and X‐ray diffraction techniques during the cold drawing process. The different structural properties such as crystallinity, crystal size, birefringence, and different orientation functions were measured as a function of the draw ratio. From the obtained thermogram, it is clear that the melting temperature of the drawn nylon 66 fibers did not show a significant change due to the cold drawing process. As the draw ratio increase, the crystallinity and crystal size increase. The drawing process improves the chain orientations along the fiber axis of nylon 66 fibers. The orientations of the chain segments enhanced due to the cold drawing process of nylon 66 fibers.

An insight into enhancing the physical properties of poly(lactic acid) (D600) fibers

“…where v c is the weight fraction of crystallinity, DH f is the fusion enthalpy, and DH 0 f is the complete crystallization heat fusion at the equilibrium melting temperature (93.7 J/g). 17 Laser diffraction was used to measure the geometrical parameters of the drawn PLA fibers, such as the transverse section shape and area. The tested fiber diameter (d) can be determined by using the following equation 9…”

“…The XRD radiation was monochromatized by using a monochromator beam made from graphite. Crystallinity can be measured by using the following equation: 17 where F cry is the enclosed area under the crystalline peaks and F amp is the enclosed area under the amorphous peaks.…”

“…8,9 The degree of molecular orientation, as one of these physical parameters, can be measured by considering the birefringence of the fiber. 17 The principal goal of this work is to elucidate the different physical properties of PLA fibers and their dependence on the cold-drawing process. The effect of the drawing ratio on different physical properties, such as crystallinity, birefringence, orientation, and geometrical properties, was studied.…”

“…8,9 The degree of molecular orientation, as one of these physical parameters, can be measured by considering the birefringence of the fiber. 17…”

Characterizing The Effect of Thermal Annealing Process on the Physical and Structural Properties of Polybutester Suture Fibers.

“…The crystallinity of the polymer is a temperature dependent parameter. The crystallinity can be measured using different techniques such as DSC, XRD, FTIR and NMR [10][11][12][13] . The chief goal of this work is to throw light on the effect of the thermal annealing treatment conditions on the diverse structure and physical properties of NOVIAL suture fiber.…”