Photolysis and photooxidation of Nylon 66

Much research has been directed towards elucidating the UV degradation mechanism(s) of Nylon 66 by using various analytical methods, but until this study, mass spectrometry had not been used as an investigative technique. Nylon 66 films (with and without stabilizing additives), fibers, and nonwoven fabrics were photolyzed (at λ≤300 nm) and photooxidized (at λ≥ 300 nm) in a specially constructed UV apparatus, equipped with a high pressure mercury vapor lamp and a reattachable trap for collecting gaseous products formed during the UV exposures. After irradiation, the gas and solid samples were analyzed by mass spectrometry. Other techniques such as chemical analysis (for carboxyl end groups, imides, and pyrroles), and IR and UV-Vis spectrometry were also performed on the solid samples. Data generated from the samples photooxidized in the specially constructed UV apparatus were compared to data obtained from samples irradiated from a commonly used xenon arc source (Weatherometer). demonstrate the loss in strength which occurs from irradiation, the tensile properties such as the energy-of-rupture, & elongation, and the breaking strength were also determined on the photooxidized Nylon 66 fabrics and fibers. The data produced in this study were combined with data from the literature, and mechanisms by which Nylon 66 degrades in sunlight are proposed.