Reconstructing the Environmental Degradation of Polystyrene by Accelerated Weathering
| Autor: | Björn Poetzschner, Martin G. J. Löder, Volker Altstaedt, Teresa Menzel, Jürgen Senker, Peter Strohriegl, Nora Meides, Ulrich Mansfeld |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Scanning electron microscope Microplastics General Chemistry 010501 environmental sciences 01 natural sciences Gel permeation chromatography chemistry.chemical_compound Polymer degradation chemistry Chemical engineering Ultimate tensile strength Polystyrenes Environmental Chemistry Particle Degradation (geology) Polystyrene Plastics Weather Water Pollutants Chemical Environmental Monitoring 0105 earth and related environmental sciences Tensile testing |
| Zdroj: | Environmental Science & Technology. 55:7930-7938 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/acs.est.0c07718 |
| Popis: | The fragmentation of macro- into microplastics (MP) is the main source of MP in the environment. Nevertheless, knowledge about degradation mechanisms, changes in chemical composition, morphology, and residence times is still limited. Here, we present a long-term accelerated weathering study on polystyrene (PS) tensile bars and MP particles using simulated solar radiation and mechanical stress. The degradation process was monitored by gel permeation chromatography (GPC), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), 13C magic-angle spinning (MAS) NMR spectroscopy, tensile testing, and Monte Carlo simulations. We verified that degradation proceeds in two main stages. Stage I is dominated by photooxidation in a near-surface layer. During stage II, microcrack formation and particle rupturing accelerate the degradation. Depending on the ratio and intensity of the applied stress factors, MP degradation kinetics and lifetimes vary dramatically and an increasing amount of small MP fragments with high proportions of carboxyl, peroxide, and keto groups is continuously released into the environment. The enhanced surface area for adsorbing pollutants and forming biofilms modifies the uptake behavior and interaction with organisms together with potential ecological risks. We expect the proposed two-stage model to be valid for predicting the abiotic degradation of other commodity plastics with a carbon-carbon backbone. |
| Databáze: | OpenAIRE |
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