Ultraviolet light accelerates the degradation of polyethylene plastics

Abstract

Polyethylene plastics are widely used in daily life in the packaging of foodstuffs, pharmaceuticals, cosmetics, detergents, and chemicals. In this study, low‐density polyethylene (LDPE) was exposed to an ultraviolet (UV) fluorescence lamp in simulated aging and degradation experiments. Ultraviolet degradation mechanisms were investigated on the surface after sunlight and UV lamp exposure. The plastic surfaces' molecular and surface degradation results were compared with their Fourier Transform Infrared‐Attenuated Total Reflectance (FTIR‐ATR) and ultraviolet visible (UV–Vis) spectra. By growing the length of exposure time increased stages of degradation were observed. After UV lamp and sunlight exposure, changing degradation levels were also determined with spectroscopic evaluations and the results were compared. LDPE was selected since it has a simple structure and a number of branched polymer structures that facilitate easily disruption of the chemical bond. Breaks in the polymer chain were easily seen in the plastics at the end of degradation and a fragile structure was formed throughout the polymer chain after accelerating UV light aging. The FTIR spectrum clarified the changed and fractured molecular bond structures of UV‐exposed polyethylene. The change in the molecular structure of the plastic caused small changes in its color and small variations in this color change were detected by recording the Ultraviolet–Visible (UV–Vis) spectrum. The Philips UV lamp's light intensity and the wavelength spectrum range were measured. The UV lamp and sun UV light doses were calculated and compared.

Characterizing photochemical ageing processes of microplastic materials using multivariate analysis of infrared spectra

“…25,38 We caution that changes in the bulk properties may not be representative of natural environmental processes and that the weathering mechanisms may differ. 59 This may be particularly relevant as UV-C is often used to rapidly weather microplastics for contaminant sorption studies 23,60,61 despite not reflecting terrestrial conditions (Figure S1). 59 Nonetheless, we propose that the multivariate approach described here can be used to photochemically age environmental microplastics.…”

“…59 This may be particularly relevant as UV-C is often used to rapidly weather microplastics for contaminant sorption studies 23,60,61 despite not reflecting terrestrial conditions (Figure S1). 59 Nonetheless, we propose that the multivariate approach described here can be used to photochemically age environmental microplastics.…”

Study on the Aging Behavior of an Ultra-High Molecular Weight Polyethylene Fiber Barrier Net in a Marine Environment

“…Ultraviolet light in natural light is located in the most deleterious radiation range for organic compounds: 295-385 nm [15,30,31], so it is regarded and proved as the most critical factor for failure of the UHMWPE fiber. Do gon [32] reported the controlling step that induces the degradation by UV. It is suggested that, after the molecular bond strengths' energy limit surpasses UV energy absorption, degradation takes place through the free radical formation.…”

Small micro- and nanoplastic test and reference materials for research: Current status and future needs

“…The process can be sped up by conducting the UV exposure continuously and using high UV intensities but kept within natural ranges. However, shorter wavelengths are more effective at degrading plastic materials, and exposing them to light containing wavelengths that include the UVC region (200-280 nm) can significantly speed up the degradation process (Lee et al, 2020;Doğan, 2021), as can using intensities above natural levels. It should be noted that UVC exposure may lead to the formation of different degradation products and oxygenated radicals compared to UVB exposure (Doğan, 2021).…”