Effects of electron-beam irradiation crosslinking on PA6 fibers

Irradiation crosslinking of PA6 fibers with and without the presence of triallyl cyanurate (TAC) was investigated. The dose for incipient gel formation was 500 kGy for pristine PA6 fibers and it decreased to 12 kGy when 5 % TAC was incorporated. Changes in structure and properties of irradiated PA6 fibers were analyzed by X-ray diffraction, infrared spectroscopy and thermal gravimetric analysis. Irradiation crosslinking improved the anti-dripping properties of PA6 fibers effectively. Irradiated samples showed an increase of the breaking strength and then a decrease at further doses due to radiolysis effect, the elongation at break decreased during the irradiation process. Irradiation crosslinking had not changed the crystal form and crystallinity decreased first and then increased to some extent. DSC measurement reported that the melting temperature decreased with increasing the dose. The thermal stability decreased after irradiation whereas the amount of nonvolatile residue at 600 °C increased as the irradiation dosage increased. The infrared spectra of irradiated samples were identical with the unirradiated, no new bands were observed.XPS analysis showed that the number of C-C band increased after irradiation which proves that branching and crosslinking has occurred.