Nylon 6,12 fibers under low-dose gamma irradiation

Abstract

Abstract One of the most important applications of gamma irradiation is in the area of polymer modification. Nylon fibers that were gamma-irradiated with a dose higher than 25 kGy show fusion temperature and fusion enthalpy higher than the nonirradiated nylon. Nevertheless, under certain applications, the influence of nylon-irradiated fibers is noticeable below 50 kGy; therefore, physicochemical characterization is indispensable. In the present work, nylon 6,12 crystalline fibers were irradiated at low dose (from 1 to 25 kGy) at environmental conditions to confirm the thermal behavior. The melting point and fusion enthalpy were measured with differential scanning calorimetry; structural changes were studied using infrared spectroscopy; and fiber surface morphology was studied using atomic force microscopy. The results show an increase in both fusion temperature and fusion enthalpy, which are effects of the newly ordered high-molecular-weight oligo­mers. Recrystallization and oligomer formation can be observed in infrared spectra. Such behaviors are directly related to the partial damage over the surface and the mechanical performance of manufactured composites.